Part ID required please

[les g]

tap it to m8
a bit of loctite or thread sealant and it shouldn,t leak air or fall out
i know the purists will be along in a minute and say you need a 6.8mm
hole for m8 but but if you have a tight 7mm hole i,d have a go at that
after all you are just blanking a hole
if you are really keen go the next size up and drill and tap m10 with a fine pitch etc
but i know what i would try first
cheers
les g