Ordered a couple of gas springs for a project that I was working on. I had a little trouble with the on-line tool and ended up calling customer service. The person at Gasspring.ca was very helpful. Tip, if you are unsure of the measurements that you need to enter into the on-line tool just click the little question marks next to the fields for further detail of what is required. My only complaint has more to do with the on-line address. "Gasspring.ca" made me think that I was ordering from a company here in Canada. I was surprised to find out it's in the US. If the customer service hadn't been so great I would have been more annoyed at this deception. Springs were delivered and worked perfectly.