Item Description Material: Stainless Steel Zinc-Coated Stud Band Width: 19mm | 0.75" Band Thickness: 0.6mm Fit For ID 1 3/16" or 30mm Silicone Hose Fit For OD 1 1/2" or 38mm Silicone Hose Size Chosen Of T-Clamp Calculate the hose Outside Diameter. For example,if your hose Inner Diameter is 57mm, add the thickness such as 5mm, then the hose Outside Diameter is 57+5*2=67mm. So you need to choose this clamp: clamp range from 63mm to 71mm. The value of your hose Outside Diameter should be larger than the first value of the clamp range, less than the second. .