depressed center wheel was made by high quality materials with strong resin ... fiber glass nets. grinding wheel,T-27 and T-42 depressed center wheels Features: high strength,durability,high efficiency and safety,etc ... steel, C and GC for glass,stone and etc. T27 Depressed Center Wheel 100 x 6 x 16mm4" x 1/4" x ... x 22mm9" x 1/4" x 7/8"50pcs/ctnT42 Depressed Center Wheel 100 x 3 x 16mm4" x 1/8" x ...