Bore cap tool HTTC-TC covers E4 and V4what tool removes those then.
If you are going to be swopping over a bore cap it is a really good idea to give the O ring on it a bit of a smear with *Hunters silicone lube.
Just a smidgen.
*Hunters is the preferred and Hope recommended lube for O rings and sides of pistons after cleaning. One bottle of it will last you decades