TR2-3B Battery box, part of the bulkhead, supplied separately. This part consists of the box that the battery sits in and includes the sides as well as the back reaching up to the rain gutter. The bracket that the 'J' bolt hooks into is also supplied on its own as BOD1-1. See below

This part is listed on the following page of the website, where further information and background reading may be found.

This part appears on the following Triumph Catalogue Plates