I designed this shade for the tower light on my pontoon boat with a threaded base.

Since conventional, halogen tower lights can get quite hot, I don’t recommend putting this shade over an incandescent or halogen bulb—ONLY USE AN LED BULB WITH THIS SHADE. I can’t make any promises on fitness for use—for example, I can’t promise it’s water tight, but it works great for me and you’re welcome to use this design and hopefully save a few dollars :)

Original model at thangs.com: https://social.thangs.com/m/1117143