For 12V DC systems. 8 ohm. Ceramic insulator with embedded coil for effective heat dissipation. 7/16” -28 thread mounting stem, 15/32” (11.9mm) long. Plated steel case, 1.32” (33.5mm) diameter, 0.88” (22.4mm) long. Black plastic knob with metal insert and set screw . With round/bar black knob imprinted “Panel Lamps”. Two blade terminals.