This is a 3D printed adapter with printed vinyl label designed to look similar to the original B122 battery and fit directly into vintage test equipment.  (These were also known as Eveready 413, Ever Ready B123, BLR-123, 20F20, NEDA 210, ANSI 210, E210, BA 305/U, ER-413, Burgess U20, RCA VS085, Mallory 413, Mallory M123, Drydex 523, Pertrix 8123, Siemens S123)

This adapter takes 20 x AG10 (LR1130) a set of which is installed.  The batteries can be changed at any time by removing the screws on the base.

This listing is for one adapter with printed label and one set of batteries installed (BATTERIES FOR UK CUSTOMERS ONLY).

The dimensions are: 25mm wide, 14mm thick and 68mm tall (from top to bottom contact).  The contacts also have the 2.5mm hole like the original to mate with the pointed contacts on some test equipment.