My 21 year old transom hatch lift support was no longer working enough to hold it open. Started last summer, and I was getting tired of being "bonked" on the head so I decided to replace it. On a mid 90's 330DA the replacement is a Attwood Gas Spring 15" Ext 20# Bl #SL13-20-1 But I could not get one on-line in Canada or at local marine stores, so I went to my local NAPA auto parts. After some page flipping they came up with a match and I am back in business. The replacement is a 15" extended. 9.5" compressed, 20 pound force with 10mm socket ends. In Canada the NAPA part # was 819-5516. They had to order it in. Took 2 days. CAD$24.