This is an ara rod holder. The rod rest swings and has a built-in spring. The stone-butt box size is: Front: 58 x 40 mm Rear: 58 x 30 mm Depth: 59 mm The pin holes for the butt end are 9mm holes located 20mm and 35mm from the front. Removing it allows you to remove the rod keeper. The anchor bolt hole diameter is 13mm. The rod used is a Daiwa Carbon Whisker Senkaku 100-gou 484. The rod, reel, and rod keeper are not included. Please check the stone-butt box size before purchasing.