44 Magnum, 5/16" x 4" x 6", SDS Carbide Bit, To Be Used With Any SDS Rotary Hammer, Maximum Drilling Depth 4", Unique Tip Geometry & 4 Flute Design Combine To Provide Up To 25% Longer Drilling Life & Faster Cutting, Design Allows Easier Centering, More Bit Strength & Lower Vibration To Provide User Comfort & Bit Durability.