Slips onto pens, pencils, markers, paintbrushes and more Diameter is variable from 1/8" to 7/16" Comes with Allen wrench for easy adjustment Weighted Universal Pen and Pencil Holder: Holder easily slips onto pens, pencils, markers, paintbrushes and more. The weighted grip has a variable diameter that can be adjusted from 1/8" to 7/16". Weighted universal pen and pencil holder comes with an Allen wrench for adjustment.