This is a custom built bar that is specifically designed for our C I Cutter. The New bar is a CSD-SP-10-50 and is designed for the newer Makita UC3551A. The older bar is a CSP-C1-9-50-SD and will only work on the Makita UC3530A and UC4030A. This bar is no longer available. Any CI Cutter purchased after 10/15/2015 will have the new Makita and new bar. The new bar (CSD-SP-10-58) will work on the older Makitas also, you will just need to run the 40 driver chain instead of the 39 driver.