You can easily remove and replace your old bases with a RAILBLAZA StarPort HD. This rectangular, 4-point installation base sports a similar size to that of Scotty, RAM, Cannon, Fish-On, and many others. Not only does this transition give you the comfort of the RAILBLAZA's slide-locking-mechanism fit to all the bases and the versatility to effortlessly re-task accessories from 1 base to another, but the transition also opens up your accessibility to RAILBLAZA's large selection of accessories and limitless rigging possibilities. The StarPort HD also is compatible with the same hardware currently used to keep your base mounted to your kayak. Other options for installation hardware include rivets, screws/locknuts, and the StarPort HD Track Mounting Kit (not included). 6"L x 4.2"W x 1.2"H.Manufacturer model #: RBSTAR-HD. Practical replacement for preexisting external mount bases from Scotty, RAM, Cannon, Fish-On, and more Rectangular, 4-point installation base Consistent with North American industry standard Compatible with same hardware keeping your base mounted to your kayak