Amazon.com: Prescott Plastics 0.5" Inch Square Plastic Plug Insert (10 Pack), Black End Cap for Metal Tubing, Fence, Glide Insert for Pipe Post, Chairs and Furniture : Industrial & Scientific
Furniture Accessories PVC Rubber Plastic Pipe End Cap Plug Caster Wheel Threaded Inserts Screw Nut Square Pipe Plugs for Steel Pipe End - China Plastic Threaded Inserts, Plastic End Cap | Made-in-China.com
Plastic Square End Caps Pipe Plug Inserts 20/25/30mm + M8*20mm Screw Leveling Foot 20mm Anti-Slip For Tumble Dryer Table Chair
Inserts for Square Tubes with M10 Metal Thread. Made in Germany (Black, 25x25mm, Pack of 36).See 2nd Image for Dimensions
Generic 50 Pack M6 x 16 mm Rack Mount Cage Nuts, Screws and Washers Stainless Steel Black Server Rack Screws Square Insert Nuts for Aud
Standard Threaded Plastic Square Tube Inserts | JET PRESS
Furniture Accessories PVC Rubber Plastic Pipe End Cap Plug Caster Wheel Threaded Inserts Screw Nut Square Pipe Plugs for Steel Pipe End - China Plastic Threaded Inserts, Plastic End Cap | Made-in-China.com
Everbilt #10-12 x 1-1/4 in. Blue Ribbed Plastic Anchor Kit with Screws (201-Pieces) 802514 - The Home Depot
4Pack Inserts for Square Tubes with M10 Thread, for 1.26"x1.26" OD Square Tube Furniture Leg Plug