SD-273180& SD-273100 - for 7/8" Tubing
SD-273175 & SD-273110 - for 3/4" Tubing

These are used at the ends of the metal hoops which hold up the fabric on a bimini. We have inserts and caps for both 3/4" and 7/8" tubing. Usually Aluminum is used, but we have found that the inserts for 3/4" tubing are almost a perfect fit in 1/2 steel electrical tubing which you can get from your local lumberyard. In fact, in the photo above, the insert (on the left) is in a piece of such tubing. If you will not be using your boat in salt water and desire a cheap and available material for your bimini, consider steel. You can buy a bender where the conduit is sold and the stuff can be painted or left galvanized.