I’ve had at least a dozen of these and they all do the same thing. They snap in the trigger hinge area. This would be a very good price if they would last more than just a few uses. The concept is great and the design, except for the one obvious flaw, is

I do not recommend, plastic breaks , handle breaks. Will not stand even low level careful iseage.

This syringe is very poor quality and has not worked out for us. The liquid vaccine constantly drips out of the barrel, and it is very difficult to draw the vaccine into the barrel. Waste of money.

On this one you really get what you pay for. Works but just not beefed up at all.