I had to order two different strut inserts. I contacted Arana with the photos and they recommended the first set (55/for) but they weren't strong enough no matter how we attached them. Arana refunded me with no refund. The second set was (100/on) ยฃ200 for two. It took us several attempts to place them so that they hold the lid fully open. The door itself weighs around 90-100 pounds but moves more than 90 degrees. Asphalt shingles make the lid so heavy. Arana was great to work with, Mina was great. Mina replied to all my messages very quickly.