RAM Ball Adapter with 1/2″ NPT Hole & Tightening KnobThe RAM-330U consists of a 1.5″ Diameter Ball, attached to a clamp base with a hole for 1/2″ NPT pipes.Features:Hardware Included: Assembly HardwareBall Size: c Size (1.5″)Weight Capacity: Standard Use: 4 lbs/Heavy-Duty Use: 3 lbsMaterials: Marine-grade aluminumWeight: 0.35lbs