Part of the RYOBI 18V ONE+ System of over 225 Cordless Tools Lithium-ion chemical composition resists drainage when idle Includes: (1) PBP005 18V ONE+ Lithium-Ion 4.0 Ah Battery Robust construction to protect against impact Recharge on any 18V ONE+ charger Charger sold separately Delivers fade-free power in extreme weather conditions Easily snaps into place and detaches with quick-release buttons Integrated LED fuel gauge to monitor remaining runtime Up to 3X more runtime