Evans EQPC1 BassDrum Head Protection

Bought to test out just to be on the safe side for my e-kit bass drum beater side. It is merely a hard plastic sticker, very thin. No noticeable change in sound or feel (for a non drummer) Was easy to stick on and looks like it stays on the and can "take a beating)
Not for double bass pedals. Came 2 in the pack so might be able to use second for double beater, but more suitable options for that (oval and not circle, so one sticker covers both beater heads)

I've had these come off the head a few times over the years, but overall, it's a great product. Protects your bass drum head from breaking, just like intented. If you play extreme metal and abuse it hard, it might start coming off after a while, but that's not a problem. They're cheap and you get them in pairs.