We had two leaks coming from the port window dogs and so I bought the ​Lewmar Drip Stop Kit from Catalina direct part #Z2854. The Kit has several O-rings and some super lube. The O-rings worked great, 2 years later with record 2020 rains here in Seattle two other dogs started leaking but the O-rings did not stop the leak. I went to our local hardware store and found similiar O-rings but 0.07mm thicker. They Worked! The O-rings that worked were #24 33/64 X 5/8 X 1/1