Features: 1) Different sizes available 2) Tapered drill rods:a) Raw materials: 55 SiMnMo, 95 CrMob) Shank size: H22 x 108mm (7/8 x 4 1/4 )c) Taper: 7, 12d) Length under collar (mm): 610, 1220, 1830, 2000, 2435, 2740, 3050,3660 3) Integral drill rods:a) Raw materials: 55 SiMnMo, 95CrMob) Shank sizes:i) H22 x 108mm (7/8 x 4-1/4 )ii) H25 x 108mm (1 x 4-1/4 )c) Length under collar (mm): 400, 800, 1200, 1600, 2000, 2400, 3200, 4000,4800d) Bit diameter (mm): 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41