Defender Security E 2293-O Diecast Vintage Lock Bit Key with H-03 Key Number, Zinc Plated The vintage lock Sets that these keys are compatible with are those manufactured by Prime-Line Products, which are designed for interior use only 1/8 in. Thick bit with one centered cut at 1/4 in. X 3/32 in Zinc Plated finish Diecast construction Key Number H03