Will this plier work on other filter sizes?

It's sized for 64.3MM filters. Smaller or significantly larger filters may not seat properly in the flutes, so test-fit before relying on it for a different size.

Can I use this on a hot engine right after shutdown?

The metal will get warm, so wear gloves or wait a few minutes. The tool itself won't be damaged by engine heat, but handling comfort matters for safety.

What if the plier slips on the filter?

Check that the filter's top collar matches the 64.3MM spec and that the flutes are making full contact. Wipe debris or oil residue from the filter surface for better grip.