uxcell 20pcs Black Plastic Square Blanking End Caps Tube Inserts 38mm x 38mm Product Mame : Square Tube Insert;Top Size : 38 x 38mm / 1.5" x 1.5"(L*W) Thread Size : 37 x 37mm / 1.4" x 1.4"(L*W);Overall Height : 17mm / 0.7" Material : Plastic;Color : Black Net Weight : 145g Package Content : 20x Square Tube Insert