The Battery Wall Charger is an extra charger for recharging the HMT-1 and HMT-1Z1. Extra chargers and cables are needed if there are multiple locations where HMT-1s and HMT-1Z1s can be charged (eg. office, workstation, tool crib, service vehicle). They also minimize downtime in case a charger is ever misplaced. Each HMT-1 and HMT-1Z1 ships with a regional charger; for international deployments or travel, regional wall chargers are also available.