uxcell 50mm Plastic Square Tubing Tube Insert Blanking End Caps 4Pcs Product Mame : Square Tube Insert;Top Size : 50x 50mm / 1.97"x 1.97"(L*W) Thread Size : 49 x 49mm / 1.93" x 1.93"(L*W);Overall Height : 18mm / 0.7" Material : Plastic;Color : Black Net Weight : 44g Package Content : 4 x Square Tube Insert