Simpson Strong-Tie Strong Tie AZK250SM Azek Deck-Drive Dcu Screw Plugs, Smooth, 250-Linear', White (400-Per Pack), Vinyl, Flat

Q: What diameter are these plugs?

I dont know the diameter of the plugs. We used them as a substitute for the more expensive Cortex, Azek plugs and for PVC trim boards. They were a perfect fit for the counter sink drill bit that is used for them. I looked up the plugs at a few retailers and they only give the size of the screws used but not the plug size. Sorry I couldn't be more accurate.