The used Canon LC-E4N Charger is the twin battery charger for the LP-E4N battery. Key features include:

Twin Charger. The Canon LC-E4N is the twin battery charger for the LP-E4N battery, which is designed for use with the Canon EOS 1D X

Backwards Compatibility. This charger is backwards-compatible with Canon LP-E4 batteries, and it charges them at a slightly faster rate than it does LP-E4N batteries.