Stainless steel sideplates, 4" aluminum sheave, needle bearing, and stainless steel axle. Part Number: RP108|Weight: 1.8 lbs|MBS: 16,000 lbs (71kN)|Rope Capacity: 5/8"|Side Plates: Stainless Steel|Mechanics: Bearing|Sheave: 4" Aluminum|Axle: Stainless Steel|Size (in): 7.5x5|Efficiency: 0.956|MBS: 16000 lbs|ROPE CAP: 5/8"|SIDE PLATES: Stainless|MECHANICS: Bearing|WEIGHT: 1.8 lbs