Here are two versions of the 3 or 4 types of pre-1966 brown '2 Skirts' still in use on the TPUD system, OR. coast. The one on the left is a Westinghouse and has the firing rest (white unglazed portion) on the bottom, typical of many 'Westy's'. The one on the right is a Victor with the V in square ink under glaze logo and is numbered 2828 with the firing rest on the crown. These are both ANSI standard type 56-1 power insulators, and if you don't know what that means, I will let you do a little research! The 'U Number' is U-869A on the left and U-880A on the right.