A SET OF 4 ZERO CLEARANCE INSERT PLATES CUSTOM MADE TO FIT DEWALT 744, 745, 746, 7480, 7491 AND 7491RS. THE INSERTS ARE MADE OF MDF. ***NOT MEANT FOR USE WITH A RIVING KNIFE.****DO NOT BUY FOR DEWALT 7485 MODELS***. THAT MODEL HAS A DIFFERENT TYPE OF PLATE ALSO FOR SALE IN OUR SHOP.. SET SCREWS ARE INCLUDED TO ASSIST WITH LEVELING THE PLATE. ZERO CLEARANCE INSERTS ARE CALIBRATED TO A SPECIFIC SAW, A SPECIFIC BLADE, AND A SPECIFIC BEVEL ANGLE. THEY CAN ONLY BE USED ON CUTS WHERE THOSE PARAMETERS ARE MET. FOR EXAMPLE, ONCE AN INSERT IS MADE FOR A STRAIGHT-ON 90° CUT, IT CAN’T BE USED ON OTHER CUTS. IF YOU NEED TO MAKE A 45° BEVEL CUT, YOU CAN’T USE YOUR 90° CUT INSERT. YOU MUST HAVE A 45° INSERT, OR SWAP IN THE ORIGINAL THROAT INSERT. EACH ZERO CLEARANCE INSERT IS GOOD FOR ONLY ONE SPECIFIC BEVEL ANGLE.---LEVELING SCREWS: DEPENDING ON YOUR SAW MODEL, THE SCREWS MAY HAVE TO BE ATTACHED FROM THE UNDERSIDE OF THE INSERT. IF THAT IS THE CASE, YOU SHOULD START AT THE BOTTOM OF THE PREDRILLED HOLES UNTIL YOU ACHIEVE THE PERFECT HEIGHTS (THE SCREW’S HEAD BECOMES AN ADJUSTABLE SHIM). ONCE YOU HAVE THE SCREWS EXACTLY WHERE YOU WANT THEM, YOU CAN GLUE THEM IN PLACE AND THE INSERT WILL SIT PERFECTLY FLUSH WITH THE SAW’S TABLE. IF ANY OF THE SCREW TIPS HAPPENS TO PROTRUDE THROUGH THE TOP OF THE INSERT, YOU CAN TAKE OUT THE SCREW, CUT OFF THE TIP AND THEN REINSERT IT.