Whether running or biking, having this secure and lightweight LED spur will help you stay seen and safe. Powered by replaceable watch batteries that offer 40+ hours of illumination. Quickly and securely attaches to heel of your shoe Super lightweight so you don't feel a thing Multi-settings for high visibility and added safety Weather-resistant so you can run longer in any conditions LED: Two LED's, 5+ max lumens Battery: 2 x 3V Lithium 2032 - Replaceable Coin Style Battery Burn Time: STEADY ON - 20+ hrs; STROBE - 40+ hrs Water Resistance: IPX3 - Weather resistant