With the addition of the RK300 Rail Mount Kit, you can locate a GM300 or GM500 Mount on stern rails, bow rails, or even downrigger booms. The mounting kit comes complete with a backing plate and two shim sets and allows you to install versatile Burnewiin Mounts on 7/8, 1, or 1-1/4 rails. Enjoy the versatility provided by the many options our universal mounts give you. One universal mount, many options: Rod Holders, Fender Cleats, Knives, Downriggers, Flag Holders, or whatever else you can imagine (no hardware included in this kit, all hardware included with mount).