... 4)sealing:metallic seal 5)MOQ:1pc Fitting1)7 7/8'' API speed droll bit2) tungsten carbide3)Medium hard with high compressive ... TCI Tricone Bit3 7/8 ,5 1/2, 6 1/27 7/8,8 1/2,8 3/410 5/8,12 1/413 3 ... Tooth Tricone Bit3 7/8 ,5 1/2, 6 1/27 7/8,8 1/2,8 3/410 5/8,12 1/413 3 ... blades)5 1/2, 6 1/27 7/8,8 1/2,8 3/410 5/8,12 1/413 3/4, 17 1 ... more information,please feel free contact to me. 7 7/8''API speed drill bit