No. 4058 Back-board with battery box polished walnut, similar to No. 4057, but some what longer, for telephones Nos. 4055 and 4056.
Net weight (excl. telephone and cells) about 2.7 kgs.
Taken from the Siemens & Halske Telephone Catalogue 1912
Last revised: November 26, 2022
FM2