Dimensions: 5/64 ", 7/64", 9/64 ", 11/64"
 
5/64'': the opening diameter is about 2mm, using 2.2-2.8mm self tapping screw
 
7/64'': the opening diameter is about 2.8mm, using 3-3.5mm self tapping screw
 
9/64'': the opening diameter is about 3.5mm, using 4-4.5mm self tapping screw
 
11/64'': the opening diameter is about 4.5mm, using 5-5.5mm self tapping screw