Magnesium Multi-Trac Groover Blade 48" x 8" with 2-1/4" spacing. Half flat half grooved face 2-1/4" grooves on centers. Creates a clean sharp groove in most concrete finishing applications. Works with 4 hole brackets. No bracket included. Blade only. Build your Multi-Trac Groover for your concrete finishing application visit our large selection of bull float handle brackets and bull float extension handles.