Bosch Jig Saw Blades are designed to cut materials quickly, smoothly and precisely. Progressor set for several materials, including one T123X for Metal, one T234X for wood, and one T345XF All-Purpose. The progressive tooth design delivers fast, high-quality cuts in all materials of varied thickness. The blades are made with quality Bi-Metal and high-carbon steel, providing precise, clean cuts. They have optimal tooth spacing, shape and cutting angle. This provides cutting speed, cleanliness of cut and durable performance. The blades have a T-shank design for maximum grip and stability; it is the industry standard and fits most professional and consumer brand jig saw makes and models, and the blades provide the best fit and long life.