Pocket housing with battery compartment, type 3 Portable housing in a modern, attractive design of black ABS plastic with finely textured surface. Available in several designs (with or without windows). All models have a built-in battery compartment that is externally accessible via a removable cover, and plastic posts for mounting PCBs or keyboards. Housing types with 4 R6 round cells are supplied with battery terminals, the types with 9V E-block batteries do not contain a battery connector. The housings for 9V E-block batteries are screwed together with latching claws and a self-tapping screw (supplied) that are for R6 round cells with four self-tapping screws (supplied).