OP4050A OP4015 OP4026 OP40201. for Ryobi 40V Lithium-Ion Battery. Output: 40V 1.8A (MAX). Do not put battery into water and fire. 【 ADVANCED HEAT DISSIPATION 】—— Bulit-in cooling system with vents on the three sides circulate air across the batteries to cool down the heat during charging.
eBay