I think for the standard A10 hub.
The BSA/Triumph TLS shoes are 1 5/8 wide and the A10 hub takes 1 1/8.
Dow offered around 9 different TLS conversions all made by a Mr Robinson from Erdington, Birmingham.
The full width 8 inch conversions came in a BSA version, which should plug straight into the A10 hub and anchor on the A10 fork lug and 2 Triumph versions which were for the pre 1966 narrow hub and the 1966/67 wide hub which took 1 5/8 wide shoes. The different width shoes are interchangable because I have done it.
Unfortunately, with the E bay item you cannot see the width of the shoes.
The photos show the components of the brake - less linings - you will se the shoes are fairky crude castings, the original levers and tie bar were from light alloy and there was no return spring on the front cam lever as fitted to the factory item.
The third photo shows the Dow Triumph plate left and BSA plate right.
The fourth photo is from the 1969 Eddie Dow price list.