The Bavaria wire hole cover - a small and important part

The wires from the mast goes into a through-hull and then into the boat, but when the mast dismounted there i a hole in the deck where water can enter. At first I used tape but found out it was possible to buy a cover to close off and seal the hole. It was found at the german site www.svb.de and called "decksdurchführung" the price for the complete cover kit was 42 US dollars.