The CP18xx are universal lithium ion battery packs compatible for a majority of laptop computers. There are three models: CP1822 (18V, 2200mAHs, 39WHs, 128?71?24mm,192kg), CP1845 (18V, 45mAHs, 78WHs, 116?71?39mm,364kg), CP1866 (18V, 6600mAHs, 118WHs, 133?71?40mm,556kg), all applicable for laptops which require an input voltage (laptop?s adapter output voltage) between 15.1- 20V, adjusting automatically by embedded intelligence device. They are the most exquisite external battery packs in the world.