Name of rubber seals around spark plugs?

Hey guys, quick question.
Anyone know what these're called?
When the rocker cover is off, the rubber seals around the edge of the spark plug recess? I believe one of mine is damaged as I've got a tiny bit of oil leaking through onto the HT Leads so figured these're the first step of action.
Unfortunately I can't find any replcaement parts and my local honda dealership are useless. They didn't know what a leak down test was....

Anyone know what these're called?
When the rocker cover is off, the rubber seals around the edge of the spark plug recess? I believe one of mine is damaged as I've got a tiny bit of oil leaking through onto the HT Leads so figured these're the first step of action.
Unfortunately I can't find any replcaement parts and my local honda dealership are useless. They didn't know what a leak down test was....
