MD-04 Sector Helmet
The MD-04 Modular is the perfect lightweight helmet for cross-country adventures. The MD-04 has all the essentials, including a list of standard GMAX® features normally only found on more expensive... Read More
The MD-04 Modular is the perfect lightweight helmet for cross-country adventures. The MD-04 has all the essentials, including a list of standard GMAX® features normally only found on more expensive helmets.
Features
- DOT Approved
- COOLMAX® CORE technology wicks moisture away from the body and is designed to keep you dry and comfortable
- Removable, adjustable and washable COOLMAX® interior allows for easy cleaning and custom fitting
- GMAX® D.E.V.S (dual exhaust venting system) top and rear vents reduce temperature by allowing hot air to escape from the top of the helmet
- Vents close to completely seal out the cold
- Adjustable mouth vent directs air upward across the inside the shield to help reduce fogging
- Lightweight Poly Alloy shell. Large size only 4lb
- Easy to use chin bar with push to open mechanism designed for use with gloves
- 100% UV400 protection face shield that comes anti-scratch hard coated for a longer lasting clear view
- Intercom Compatible
How to measure
Measure the circumference of your head one inch above the eyebrows and across the largest portion of the back of the head, then find the matching range. The crown should apply snug, even pressure and cheek pads should be snug (they break in with use). If the helmet moves on your head it is too loose; if it causes pain it is too small. If between sizes, size down.
GMAX size chart
| Size | Head circumference (cm) | Head circumference (inches) |
|---|---|---|
| YL / XS | 53-54 | 20 7/8 - 21 1/4 |
| S | 55-56 | 21 5/8 - 22 |
| M | 57-58 | 22 7/16 - 22 13/16 |
| L | 59-60 | 23 1/4 - 23 5/8 |
| XL | 61-62 | 24 - 24 3/8 |
| 2XL | 63-64 | 24 13/16 - 25 |
| 3XL | 65-66 | 25 5/8 - 26 |
| 4XL | 67-68 | 26 3/8 - 26 3/4 |
Youth sizes
| Size | Head circumference (cm) | Head circumference (inches) |
|---|---|---|
| YS | 49-50 | 19 5/16 - 19 11/16 |
| YM (= XXS) | 51-52 | 20 1/16 - 20 7/16 |
| YL (= XS) | 53-54 | 20 7/8 - 21 1/4 |
One universal GMAX chart covers the whole lineup (street, dual-sport, snow). Youth and adult small sizes share shells and are dual-labeled: a Youth Large is the same fit as an adult XS.
Manufacturer sizing data · verified July 8, 2026