Updated December 1st, 2023

The OutdoorMaster Diamond MIPS Ski Helmet is the latest offering from OutdoorMaster. It offers many upgrades from their very popular Kelvin helmet including MIPS. It still comes in at under $100. We got our hands on one to ski with this winter. Keep reading to find out how it performs.
Overall Score
What we liked:
- MIPS and ASTM2040F-18 certification
- Goggle anti-fog vents
- Very comfortable to wear
- Adjustable vents
- Polycarbonate In-Mold construction
What we didn’t like:
- Styling is a little on the bland side
- No XL or Asian fit sizes are available

- ULTIMATE PROTECTION – Equipped with MIPS (Multi-direction Impact Protection System) and REINFORCED PC SHELL & SHOCK-ABSORBING EPS CORE with in-mold construction. This ski helmet is LIGHTWEIGHT and DURABLE, built for both comfort and maximum safety.
- SAFETY CERTIFICATION – ASTM2040F-18
- WEIGHT – 15 Ounces
- BEST-IN-CLASS VENTILATION – Equipped with 11 individual vents(including four that can be adjusted by a toggle switch) for next-level ventilation for HOURS OF COMFORTABLE SKIING.
- GOGGLE DEFOGGING VENTS – No more foggy goggles!
- ADJUSTABLE SIZE – Size adjustment dial for a perfect fit.
- EASY TO CLEAN – Removable ear pads & inner fleece liner.
- SEAMLESS COMPATIBILITY – Ski helmet is compatible with OutdoorMaster ski goggles & helmet drop-in headphones. Listen to your favorite music while skiing
OutdoorMaster Diamond MIPS Ski Helmet Review and Test


The OutdoorMaster Kelvin is a great helmet for the price retailing at under $40. It is missing several features that most skiers beyond the beginner stage want. This includes MIPS for maximum safety, adjustable venting, and goggle defogging vents. The Diamond includes all these features and more. As a bonus, it comes with a helmet bag.

Price
The Outdoor Master Diamond retails for $99.99 just getting in under the $100 price point. Using our discount code ERO15 you can get it for $85. The helmet is also available on Amazon for the same retail price but without any discount codes.
Construction
The Diamond looks a notch more upscale than the Kelvin. It does not have exposed rivets holding on the straps. The helmet uses in-mold construction so the bottom of the shell has a rolled under molding. The Kelvin with ABS shell and glued in liner has a noticeable seam around the edge between the shell and EPS liner.
The Diamond has a PC (polycarbonate) shell with in-mold foam liner. This means that the EPS foam is molded into the shell and not created as a separate mold. This allows for much tighter tolerances in the parts and a better helmet appearance. It has other benefits such as more intricate air vent openings and channels are possible.

My Diamond MIPS helmet in size large weighed in at 15 ounces. My Anon Echo MIPS helmet weighs 1 lb. The Smith Mission MIPS helmet I reviewed earlier this winter weighed 1 lb 1 ounce. My OutdoorMaster Kelvin helmet weighs 1 lb 1 ounce. The Diamond has a very competitive weight for a MIPS ski and snowboard helmet intended for resort skiing.

MIPS – Multi-directional Impact Protection System
MIPS is a layer in your helmet under the energy absorber that allows the helmet exterior shell to rotate relative to your head. This means that for angled impacts such as a glancing blow, the helmet shell will rotate without transferring the rotational force to your head. This reduces the forces going into your head and spine reducing your risk of injury. Learn more about MIPS here.

Safety Certifications
The helmet is certified to ASTM 2040F-18 safety standards. The helmet has a tag inside displaying the cert information.
Removable inner fleece liner
Inside the helmet, you will find the yellow MIPS liner and a removable fleece and mesh lining. The fleece liner feels like a similar material to the Kelvin helmet. It is warm but can get saturated with sweat on warmer days. It is easy to remove for cleaning.

Audio compatible removable earpads
The earpads snap in and out with plastic tabs. They are completely separate from the interior lining. They have a similar fleece lining on the inside. They have velcro pockets for installing blue tooth speakers. The helmet lining also has a channel for passing the wiring around between the speakers for a neat clean installation.
Check out the Outdoor Master BT01 wireless headphones for a set of speakers that work well with the Diamond MIPS snow helmet.
See our guide to the best ski helmet speakers to learn more.

Chin strap
The chin strap has a fleece covering that is smaller profile than what was found on the Kelvin. It’s in line with the padding size you will find on a Smith, Oakley, or Anon helmet. It has plenty of extra length. I wear a size large helmet and with a hat and neck gaiter I still have some extra chin strap to go. I am at the end of the adjustment range on the Kelvin helmet wishing for another inch. I’m really happy to see they made this change.
Adjustable venting
The helmet has 8 vents. The 4 on the top of the helmet are adjustable with a standard slider on top of the helmet. The slider feels smooth and easy to adjust. The OutdoorMaster website claims 11 airflow channels in the helmet. I can count 10 if I count 2 for the goggle/front vent, 1 for each vent on top of the helmet and 1 for each vent on the back of the helmet. I’m not sure where the 11th air channel comes from.

Goggle anti fog vents
The 2 front vents work as anti fog vents for your goggles. They work by drawing air through your goggles and passing it around your head. This increases the airflow in your goggles which helps remove fog. This system helps a lot with keeping your goggles clear. They will clear any fog up right away when you start skiing that build up while you were standing around.

Bungee goggle clip
They got rid of the plastic clip and used a bungee attachment to retain your goggle straps. Smith uses a similar bungee system on their high end Quantum and Vantage helmets. I am worried that the plastic clips used on most low end helmets will break off flexing and exposure to UV rays. Having used a Smith helmet with this feature for years I really like it.

Appearance
The helmet has a plain dome shape with a small brim in front. Mine is the Meteorite Black version with has a nice black matte finish everywhere. The vents are don’t have any character or shaping to them. The lower shell molding that wraps around the bottom comes in contrasting colors on some models. This helps give the helmet a little more character. I wish the helmet had a few more character lines and shape to give it a little more dynamic appearance. It has similar styling to the Smith Scout/Maze, Oakley Mod 1, Anon Rodan, and Giro Ledge helmets.



Fit
The Diamond helmet comes in small, medium, and large. The size ranges are as follows.
- Small 20.1-23.3 inches
- Mediun 21.7-22.8 inches
- Large 23.2-24 inches
It has a standard size adjustment dial on the back. Like the Kelvin helmet, the adjuster is easy to use and has a smooth quality feel to it.
The OutdoorMaster Diamond size large has a specified size range of 23.2-24 inches. The OutdoorMaster Kelvin helmet had a size large with a size range from 22-24 inches. I have size Large helmets in both models. When I put them on, the Diamond physically feels larger. The inside of the helmet is wider. I can fit a finger up each side of my head in the Diamond. I cannot in the Kelvin.
The Kelvin ear pads just barely reach the bottom of my earlobes and don’t quite cover the tips. The Diamond ear pads have a solid half inch overlap extending past the bottom of my ear lobes.
The helmet is comfortable to wear. I don’t have any pressure points when wearing it. The earpads feel good with nice pockets to keep them from pressing into my ears. I get headaches with a lot of helmets due to ear pressure. Any helmet that doesn’t so that I can leave the ear pads on is a bonus.
Goggle Compatibility
I have tried this OutdoorMaster ski helmet out with most of the OutdoorMaster goggle lineup including Ultra XL, Vision XL, Pro XM, and the OTG. It works really well with any OutdoorMaster goggles with no goggle gap and a nice fit around the sides.
OutdoorMaster Diamond Snow Helmet with MIPS

OutdoorMaster Discount Code
Use the Coupon Code ERO2022 for 10-20% off at OutdoorMaster.com
The Verdict
This OutdoorMaster Diamond MIPS helmet is a nice upgrade from the Kelvin helmet. It has real upgrades such as MIPS, adjustable venting with goggle anti fog vents, and a wider shape that make it well worth the increase in price. I highly recommend anyone looking for a full feature ski helmet to check it out.
See our Ski Helmet Gear Guide to see our best ski helmet picks.
You might also like:
- The OutdoorMaster Ultra XL Snow Goggle Review – The Best $100 Ski Goggle Ever
- The Best Ski Helmets Under $100 of 2023 Helpful Guide
- The Best Ski Goggles of 2023 Gear Guide – Reviews, Ratings, and More

Doug Ryan
Co-Founder & Chief Editor
I grew up back east in Pennsylvania and learned to ski on a family trip to Killington, Vermont when I was 6. I immediately fell in love with the mountains and outdoors and have been skiing across the US and Canada ever since. I went to school for Mechanical Engineering, and have a Master’s Degree in Material Science and Reliability.
I am a total gear nerd and love learning how things work and thinking about how they could be improved. Nothing excites me more than trying out new gear. I’d rather spend 3 hours taking my bike apart and learning how to change something than go to a bike shop. These days I reside in Michigan by the Great Lakes and go skiing, biking, and boating as much as possible.
doug@adventuregearinsider.com