RYOBI P107 One+ 18 Volt Compact Lithium Ion 1.5 Ah Battery (Single Battery) FUEL GAUGE: Know how much charge you have left in the battery with the LED lighting system on the front, activated with a button COMPACT: Power your tools with less weight than the bulky 4Ah batteries, allowing you to physically work for longer and bring your tools into tight spaces ONE+ COMPATIBLE: These batteries work with many tools in Ryobi’s One+ lineup. That’s more than 50 tools this is compatible with, from reciprocating saws to shop vacuums FADE-FREE POWER: These batteries will work as powerfully as they were when fully charged until they completely run out