Type III HA Black Crenelated MDX-16.5 Head . The opening at the front of the head is 16.5mm. It comes with an aluminum lamp retaining washer, head gasket and lens. This will fit the MD2, MD3, And MD4 bodies. All M series dropins will physically fit this head. It is up to the end user to determine that the voltage is correct. Although the M61T will fit, it is better ulitilized in the MDX-22.3 Head.
Does Not Include M Series Lamp Assembly!