Item Description T-Clamp *2 Material: Stainless Steel Zinc-Coated Stud Band Width: 19mm | 0.75" Band Thickness:0.6mm Fit for ID 1-3/16" 30mm Silicone Hose Fit for OD 1-1/2" 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. .