The AK 20 battery features increased performance over the previous model and runs at full power over the entire battery run time. Easy-to-read LED display lights indicate battery charge. Compact and lightweight, this battery provides optimal power and performance for your AK System tools with minimal loss of charge during storage. Ideal for select AK System tools, the AK 20 battery provides optimal run times for the MSA 120 C-B, FSA 60 R, HLA 56, HTA 50, BGA 57, and SHA 56.