Excalibur Fibre Cement Shear Head Kit Fits most power drills but best purchased factory fitted and tested with two-year warranty on the complete unit - available factory fitted on mains (240 Volt), cordless (14.4 Volt battery) and air motors - suitable drills include the following features     - 43mm diameter neck, 15mm long     - 3/8" or 1/2" UNF shaft     - capable of accepting substantial shaft side loads Cuts up to -9mm (3/8") non compressed fibre cement sheet -6mm (1/4") compressed fibre sheet -16mm (5/8") plaster board Minimum dust Curves and straight One handed operation Can be rotated 360 degrees on motor for the most comfortable operating use Interchangeable with Excalibur Sheet Metal Cutter head.