3M™ Cubitron™ II Hookit™ file sheets 737U combines the highest 3M™ technology for automotive repair. Its long-lasting triangular shaped grains make the sheet ideal for paint stripping, rough shaping of body filler and sanding plastic filler. Hookit™ system makes for quick change outs of abrasive sheets. Cubitron™ II Hookit™ file sheets 737U for superior cut and long life during key stages in auto body repair. Its long-lasting triangular shaped grain and multi-hole pattern for superior dust extraction make the sheet ideal for paint removal, rough body filler shaping, fine feather edging or final prep before blending or priming. Hookit™ system makes for quick change outs of abrasive sheets. This abrasive is ideal for feather edging, as a final sanding step before priming or during prep before blending.