These are good quality and a good value. I used them for a couch table so I plugged the drainage hole with some caulk. I don’t understand why a drainage hole would be beneficial. If you use them for your car then the liquid is just draining into your car console, same goes for use in a boat. If I left them open in the couch table then condensation from drinks would look at the bottom and drop onto the hardwood floors.

- Dimensions: 3-1/2 H - 3 1/2"ID, 4 1/8” OD, with flange
- Install almost anywhere on boat, game table, sofa, cars and RV.
- With drain holes in the bottom to keep moisture away
- Install almost anywhere; table, counter top, dashboard, seatback, etc.
- No Mounting Screws Required Smooth Finish For Easy Clean Up
Question: what size hole saw will I need to install these?
Answer:
I’m pretty sure they’re designed for a 3 3/4” hole saw; I used a 3 5/8” hole saw because I wanted them to be very snug.