Anodised 6063 alloy housing is durable and allows heat to dissipate quickly. Acrylonitrile Stirene lens is the same material used in automotive headlights, is UV resistant, shatterproof, and offers high clarity Durable silicone backing and strap to suit a variety of bars and seat posts. Alloy shield protects your eyes from glare from the light. Angled rear light to accommodate sloping seat posts. Batteries included 2xCR2032 (Each light) Each light features one super bright led suitable for being seen while on the bike Function - Steady (60 hours) - Flashing (120 hours)