The compact, lightweight AK 10 battery weighs in at 1.8 lbs., featuring an updated battery face design with the same exceptional power as the previous model. Ideal for select AK System tools, the AK 10 battery provides optimal run times for the MSA 120 C-B, MSA 140 C-B, FSA 57, FSA 60 R, HLA 56, HSA 56, BGA 57, and SHA 56 providing full power over the entire run time. The LED light display lets you know the status of your battery's charge. Enjoy clean-running power and performance with the STIHL AK 10 battery. The redesigned 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.