The units for sale are IMPROVED reproductions of first commercially marketed #6 dry cell battery produced by the National Carbon Company (NCC) with the Columbia label in 1896.  The improvement is the visibility of the simulated top rim of the zinc canister surrounding the sealant on ttop of the original #6 dry cell. 

NCC was the primary source of dry cells for farm and home uses, the auto industry, and telephone companies in the early 1900s.  In the early years of production of the #6 dry cells, the negative terminals were 8-32 screw binding post type, and the center terminals were on an extended carbon slab post.  

To meet increasing telephony demand the Western Electric Company (WE) began producing dry cells with its' Blue Bell label for the Bell System Companies around 1907.  NCC remained as an additional source for Bell System companies until at least the 1900 mid-teens. 

So if you have a single box wood wall phone of any manufacturer produced between 1900 and 1907 this reproduction dry cell could be historically correct for display inside.   This Columbia label, and the first WE Blue Bell label appear in the 1907 Western Electric Apparatus Catalog.  Original manufacture of these phones included spaded battery leads. 

My dry cell reproductions are configured to produce 1.5V each with two D-Cell battery holders (wired in parallel), and feature top access to allow easy replacement of the batteries (not included) when necessary.   Dry cell dimensions (7”H X 2-5/8” Dia.), weight (2 lbs. W/D-Cells), label graphics and colors are nominally consistent with the original battery of this era equipped with the carbon slab center terminal.  The tops are potted with sealing wax over epoxy which is similar in appearance to Pitch which was used in the original production.