Garelick Low Profile Seat Slide and Locking Swivel Features Allows helm or boat seats to adjust fore and aft Slide mounts under seat in between seat and pedestal base Convenient handle provides solid locking at any position Compatible with most 360 spiders Wobble-Free DesignOperation 6 Travel, standard size for wood or plastic seats Anodized aluminum with stainless steel hardware. Spider swivel casting not included Specifications 7.5 19cm Fore and Aft Travel 8.5 W x 8 L x 4 H 22cm x 20cm x 10cm