Cygolite MityCross 400 Li-Ion Dual High-Brightness LED system Stem-mounted lithium-ion battery, system has 6 modes, palm-sized Li-Ion battery On-site programmable technology, smart rapid charger, helmet and handlebar mounts Cross-Fire technology crosses beams to double viewing area Runs for up to 17 hours on low setting, weighs 0.53-pounds Handlebar and helmet mounts included