I ordered the exact same part number listed on both pieces needing replacement. They have been in my possession for at least 12 years I believe, and never out of service. For some reason I mistakenly ordered ONE instead of ordering TWO my bad. However, installing the new Gas Spring to replace either of the existing, the cover is never held open to the extent the old Gas Springs are able to accomplish. I would order another but why purchase new when the old is closer to accomplishing the task. I have two old Gas Springs that need to be replaced, AND a brand new Gas Spring that isn't worth it's weight for shipping. Should I take the springs off the cover and take an accurate weight? Please phone or email advice. Frank Smoak 843 834 9162 sales@gunsmoak.com