Reproduction Transfer Port Gasket 27-20030 used with the single cover used on many Mercury engines.  KG and earlier series, Mark 20H, Mark 30H, Mark 55H and many more Mark series engines.  The price for a single gasket is $1.75, a pair is $3.00 and a set of four is $5.00.  Lets us know how many you need and we will invoice you accordingly.