With two rotating R-Lock friction joints and a knuckle joint that tilts in 15° increments, the RAILBLAZA Adjustable Extender R-Lock adds great versatility. When coupled with one of RAILBLAZA's large range of accessories, it helps keep hold of your Fillet Table, fish finder, or any number of useful items. Base not included. When coupled with one of RAILBLAZA’s large range of accessories, the Extender is a great addition to help keep hold of your fishfinder or any number of useful items.