140 Count, 9" x 1-5/8", Steel Flat Head Square, Backer On Cement Board Screws, Serrated Head Design For Flush Seating Even At An Angle, T-25 Bit Provides Stick Fit For Easy 1 Handed Installation, Patented Design Allows Attaching Close To Edge On Cement Board, Drastically Reducing Fractures Or Blow Outs, Use To Attach Cement Board To Wood Or Light Gauge Steel Studs, Ideal For Use In High Moisture Areas.