Troy Lee Designs knew it wasn't easy to improve upon the class-leading design and function of the D3 helmet, but they made it happen. Built with an aerospace shell design and materials, TLD was able to get the D4 Composite helmet to 1050 grams without sacrificing any strength. MIPS C2 protection system is used to add an additional layer of safety in the event of a fall. For comfort, the D4 Comp routes cooling air through a front air intake system that flows through the polymer center and power grid side mesh keeping your head cooler during the those hard-core training sessions. X-static® and XT2® anti-microbial/anti-odour padding keep the inside of the helmet a much nicer place to be, and when you leave it in the car overnight, it'll keep the peace when mum jumps in it the next morning.
How to measure:
Use a soft tape measure to measure the circumference (around) your head an inch (2.54cm) above your eyebrows. Keep the tape level front to back. If you don't have a measuring tape, use a peice of string, shoe lace , spaghetti* or snake* then lay it out on a table and measure it with a ruler.
*Make sure the spaghetti is cooked/ or the snake is asleep.
** LUXBMX does not recommend using a snake to measure the circumference of your head.