Hanperal 2 Pcs Plastic Flush Mount Fishing Boat Rod Holders and Cap Cover Kayak Material: PC+ABC. Length: Approx 19cm / 7.5 inch. Inner diameter: Approx. 45mm inside tube Diamater. It's a great tools for you, suitable for hold the fishing rod on your Kayak. Package Included the mounting screws, easy Install and ready to use.