Compact, bright, & versatile, the Vi Z150 stands out with high visibility from Opti Cube™ lens technology & Daytime Hyperflash™ mode in an economical package. 3 LEDs (150 lm) Highly visible during daytime 300 degree visibility Long rear beam projection Opti Cube™ lens technology Lithium-ion rechargeable battery USB (Universal Serial Bus) rechargeable (Micro-USB cable included) Low battery indicator 4 modes * Charging time: 3h Mode memory function Battery Auto Save (The mode automatically changes to flashing when the battery power gets low.) New seat post bracket SP-15 which fits contemporary (kammtail) aero seatpost Snap System™