Xnito is the top choice for classic design and certified protection, perfect for bicycles, e-bikes, e-skateboards, e-scooters, One Wheels, and other PEVs up to 28 mph. Upgrade your safety today with our NTA-8776 certified helmet and join us in our mission to help the environment - for every purchase, we plant one tree. HELMET WEIGHT: 0.83lbs (375 grams) HELMET CONSTRUCTION: In-Mold (PC, EPS) HELMET VENTS: 10 vents HELMET CERTIFICATION: CPSC, CE, NTA-8776 SPEED PROTECTION: Up to 28 mph (45 km/h) VEHICLE TYPE: Class 3 e-Vehicle | Electric Bike | Electric Skateboard | Electric Scooter | Roller Skate | Bicycles | OneWheel | Electric Unicycle LIGHT FEATURES: USB Rechargeable 3 Light Modes (Flash, Static, Wavy) Lasts Up To 10 Hours Water-Resistant (IPX4) Medium size: 21.2 - 22.8 in (54 - 58cm) Large size: 22.8 - 23.6 in (58 - 60cm)Extra Large size: 23.6 - 25 in (60 - 63.5 cm) HOW TO MEASURE YOUR HEAD Wrap a soft, flexible measuring tape horizontally around your head 1 inch above your eyebrows and ears. Pull the tape softly snug, read the length and repeat for accuracy. Use the largest measurement. Select the helmet size that is closest to your head measurement. Helmet return policy: To ensure the safety of all of our customers all helmets are final sale. To ensure the safety of our clients all helmets are always final sale. This ensures that your helmet purchased form us is always in new condition.