Sunrimoon CS-07 Zeta Bike Helmet - Classic Black Size:M (54-57cm) engineered for even greater durability

engineered for even greater durability and performane while maintaining a significant weight advantage over other drivetrain solutions

For tyres larger than 29x2

XS S M ML L XL A SEAT TUBE LENGTH (mm) 425 445 470 500 530 560 B SEAT TUBE ANGLE 74

Innovative 1 bolt clamping system

Sunrimoon CS-07 Zeta Bike Helmet - Classic Black Size:M (54-57cm) engineered for even greater durabilityCS 07 ZETA The seven air inlets at the front end and the seven exhaust vents at the rear work in tandem to effectively equalize the air flow ratio. the helmet is reserved for the tail safety warning light interface (optional), which can significantly improve the safety of night riding. Ride in the bold color of ZETA and let every mile reflect resilience and power. 3D GRID Elastic Matrix System This system uses a 3D GRID, a "dense soft supporting body"