Inner Diameter: 30.5mm/1.2 inch; Outer Diameter: 53mm/2.08 inch. Length: 76mm/2.99 inch; Center Ring Size: 39mm x 24.5mm x 8mm/1.53 x 0.96 x 0.31 inch. Clamp made of Stainless Steel, resistant to corrosion and high temperature.