"The RAILBLAZA Rotating Platform S is the ideal mount for devices that require less flexibility, such GPS devices and depth finders. The Rotating Platform holds the device in place and can turn a full 360. Made from a combination of high-quality UV-resistant engineering plastics and UV-resistant high-density polyethylene (HDPE), the platform can be used as a flat surface to make many items StarPort-compatible. Once you have finished using the platform it can be removed and the StarPort can be re-tasked for another application. The Rotating Platform fits in any of the RAILBLAZA bases. Base not included. 4""L x 4""W x 2""H.Manufacturer model #: RBRP. Rotating Platform holds GPS devices and depth finders in place. Rotates 360 Made from UV-resistant plastics and HDPE"