Nothing can bite through these, at least nothing we keep in our tanks. They are a pain to put on and even though they go way up the shoulder water inevitably gets in, then its a week of drying to clean them out. I recently redid the aquascape in their tank and I wouldn't have been able to do it without these. Prior to the aquascape redo I killed a ton of aiptasia with aiptasia x. Part of the reason I let it get out of control in here is I just didn't want to deal with her attacks. At first she would attack the syringe, but later realized she got more of a reaction from the hand.
I got mine in October of 2018. There was a size difference but they were still quite young. I used a divider when they were in QT and they still got through. The poor male healed maybe 10x and the last time I introduced them together when I found them (despite checking frequently) she was beating his dead body!
After that she lived alone until summer 2019. It was a similar scenario this time but eventually I did get them to pair up. So she was alone from about November to July and just as mean in that time frame.