4-1/2" Diameter Blade General Purpose Premium Bosch parts keep your tools working their best for any application you can come up with. Bosch blades are needed to be replaced often for safety and insure the job is done correctly the first time. Features: 7/8" Arbor 4-1/2" Diameter Bosch has been in the headlines of state of the art development for over 100 years. From the invention of the jigsaw to their ergonomic designed tools, Bosch as cared about the customer since they started business in 1886.