12 mm V-Tip segments and grade A diamond crystals for super aggressive drilling Laser welded segments and thin wall steel core for reliability Medium bond for general purpose drilling a wide range of construction materials Suitable for both dry and wet use For core drill stand rig with 1-1/4 in. -7 Spindle Premium quality diamond core drill bits with v-tip for concrete drilling by Archer PRO. American designed for high performance and long life. Optimized for a wide range of construction materials including concrete, masonry, pavers, bricks and blocks. Ideal for both professional contractors and DIY users.