SPECIFICATION. Down cut router bits 1-1/4" cutting length; 3/8" cutting diameter; 3/8" shank; 3" overall length, can be used on routers with 3/8" collect. DOWN CUT. Spiral bits used for smoothly downcut groove and slots, Mortises, Cycles and dados leave with clean edge and top surface, better than straight bits COMPATIBILITY. This Router Bits is perfect for soft woods, hard woods, Plywood, laminate, OAK, MDF and any hardwood working. It can be used with cnc router and handheld router with 3/8" collet. DURABLE AND PRECISE. This Downcut router bits are high-quality construction ensures durability and precision, allowing for consistent and accurate cuts. VARITY USE. Excellent choice for dado, rabbet, mortise, pocket, profile cutting and clearing material