I have had this lash curler for quite some time. In fact, I have lost one of the silicone inserts for where your finger goes. I would say it is around 2 years old and it still has strong tension.
I find that it gives me sizeable curl without having to hold the curler down for longer than 5-8 seconds. I hate having to hold a curler a long time on my sensitive lids, just too much pressure. That's why I like that this one produces a noticeable effect in a short amount of time.
The company offers a lifetime guarantee on their implements.
If an item loses tension or breaks or anything, you have that recourse. I once took them up on that guarantee because of a pair of splinter tweezers I had that got really dull and a eyelash curler that lost so much tension that it did not produce any curl no matter how long I held it on my lashes. I had to send the items back to them, but they sent me new items to replace my defective ones. They won't honor rusted tools or ones they deem "abused."