Greenworks battery charger. Compatible only with Greenworks 40v lithium ion battery models GWG40B2 (29717) and GWG40B4 (29727).Features and Benefits• High Performance 40V Lithium-Ion Battery Charger for low cost operation.• Energy Star Rated. • Quick battery charge time: 60 minutes for 2 Ah Batteries & 120 minutes for 4 Ah Batteries.• Compact design for easy storage.• Can be wall mounted.