The Symbol 3864 Single Slot Cradle is used to charge the LRT 3800, LDT 3805, LRT 3820 and LRT 3840 s batteries as well as enable intercommunication between the terminal and a host computer. You can optionally communicate with the 3864 cradle with an integrated modem. The 3864 Single Slot Cradle is also equipped with a spare battery charger slot so that the terminal spare battery can be charged.