AO3 Vented ABS Shortpeak Comfort Safety Helmet. EN397 approved. Durable ABS modern shell design. 30mm short peak. Comfort 6-point terylene head harness. Comfort fitted foam sweatband. Vented for increased air-flow. 30mm accessory slots for earmuffs, visors etc. Unique patented Push-Lock head harness, adjustable from 53cm to 65cm head sizes.