This is a 3D printed adapter with printed vinyl label designed to look similar to the original B121 battery and fit directly into the Avometer MK8 and other models.  (These were also known as BLR121, 411, 101, 10F20, A411, UG411 or U10)

This adapter takes 10 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 36mm tall (from top to bottom contact).  The contacts also have the 2.5mm hole like the original to mate with the pointed contacts on the Avo.