The Mincon MC series Drill Bits do not use Foot Valves (Blow Tubes) and therefore any problems previously associated with them are completely eradicated. The multi splined, full length drive bits are designed to extend the wear life of the bit shank. Like all Mincon DTH hammers, the Mincon MC80 maintains excellent operating pressure over an extended service life and overall is the tool you require to get the maximum out of all your equipment. Mincon Products are all manufactured in house, and all processes are carried out under the one roof. This guarantees that the quality you "Expect" is always delivered. DHD340A, DHD350R, DHD360, DHD380; Cop32, Cop34, Cop44, Cop54, Cop64, Cop84; Mission 40, Mission 50 , Mission 60, Mission80; SD4, SD5, SD6, SD8; TD40, QL50, QL60, QL80; BR2, BR3. Carbide button shape selection: 1. Domed/Round Button 2. Parabolic/Semi-Ballistic Buttons 3. Ballistic Button 4. Sharp Button 5. Flat Button