Slab Slayer when you purchase the Tite-Lok Ultras they make two type. They make one with a square base called the Ultra that fits in the track mount on the boat and they have one called a Ultra Supreme with an oval base that also fits in the track mount on your boat. You want that oval base it gives you so much adjustment. In other words it is not fixed you can turn the whole rod holder to either side. Look at www.crappiestuff.com, there it is called the Ultra Supreme. Ask for Jeannie she is a really cool person, loves to talk about crappie fishing. On my boat I have 9 six inch tracks mounted between the front and the back decks. This way I can have a mount in seconds whereever in the boat I may need it whether it be for slow vertical trolling, longlining, or for night fishing . The regular Ultras with that square base does not give you that kind of ability to make adjustments. The Ultra Supremes are worth every penny extra for that kind of adjustability.