Air Backfill Tamper Hole Diameter 5 3/4 in Piston Bore Size 2 in Piston Stroke Length 4 in Maximum Blows per Minute 1 750 bpm Butt Diameter 5 3/4 in Tool Weight 47 lb Air Inlet Gender Female Air Inlet Size NPT Air Consumption 36 cfm Air Inlet Type 3/8 in NPT Female Duty Heavy Handle Type Straight Minimum Hose Size 1/2 in Primary Material Application Concrete Product Type Backfill Tamper Retainer Type Latch Series 441 Series Sound Level 95.4 dBA Standards ISO 15744 ISO 28927