What is shown on the website is what I was looking for. What I received does not match the description. There is only a thin head on the cap, and the cap diameter is 1 11/16 and will only fit 1.5 ID tubing. They will not work in a 1.5 OD tube. Maybe they didn't send it. See photos. To update. The seller tries to fix the error. I'll let you know I'm outraged. Update 2: Seller sent replacement immediately. Perfect for what I need. Excellent customer service.