This indicates a set of four replacement batteries for Milwaukee cordless tools that operate on an 18V lithium-ion battery system The 9.0Ah capacity suggests that each battery has a high capacity of 9.0 ampere-hours allowing for longer usage time between charges compared to standard batteries
When purchasing replacement batteries it's essential to ensure compatibility with your specific tool model and to buy from reputable sources to quality and safety
Capacity The 9.0Ah capacity indicates the amount of charge the battery can hold Higher capacity batteries generally provide longer run times between charge swhich can be advantageous for longer jobs