Specification: 12pcs/set. This kit contains 9pcs diamond core drill bits(6/6/8/19/25/35/50/75/102mm); 1pc 4/5" diamond finger bit; 1pc 2" diamond chamfer bit; 1pc connect 5/8"-11 thread to SDS adapter. Application: EXFEIN core drill bits are used to drilling holes; finger bit for enlarging holes; chamfer bit for trimming holes; For porcelain ceramic tile marble granite, etc. Dry or wet use. Wet drilling with less debris for longer life Machine: 5/8" arbor angle grinder. Diameter less than 4": Recommended speed 6000RPM; Maximum speed 11000RPM. Diameter 4": Recommended speed 3000RPM; Maximum speed 6000RPM. SDS adapter in this kit can be attached to a drill bit with a 5/8" fitting so that the drill bit can be attached to your drill machine with sds-plus thread. If you are using this kit on a hand drill, make sure that the drilling speed does not go below 2000 RPM. and do not use the impact drill mode. Durability: Vacuum Brazed technology combines a high-quality steel matrix with diamonds in a scientific ratio and provides high efficient working performance and longer service life. Fast drilling: Lightning teeth has wide chip removal slots, dust can be quickly discharged when drilling, not easy to be clogged. EXFEIN Diamond Tile Hole Saw Kit 12pcs - Diamond Core Drill Bits 6/6/8/19/25/35/50/75/102mm for Tile Porcelain Ceramic Marble with 4/5" Finger Bit and 2" Chamfer Bit Trimming Holes and SDS Adapter