Brown and Barlow (B & B) float chamber top feed nut solder tail for 1/4 inch copper pipe. 9/16 inch x 24TPI thread. Suits 1915 model. Original part number 012 - petrol union nut (1916-23); 112 (1924-26) 013 - petrol union (1916-23); 113 (1924-26)