Hi Folks. I'm not a gun guy per se , not an expert or even a very good shot. I got my Glock 19 after all the craziness going on all over the place. The fact that Glock does not have a separate manual safety switch bothered me so I had a Cominolli Manual Safety Switch added to my gun in Jan 2020. Just recently while at the range I had the safety fail. It caused the trigger to become pretty rough and became progressively stiffer , ultimately leading to the trigger jamming and being unable to fire. A local gun smith explained that the safety was interfering with the Glock's mechanisms. ( something shifted and he pointed out the tab or shim what was out of alignment etc. ) He removed the entire safety mechanism in order to remedy the issue. I imagine better maintenance or diligence of the add on switch would probably have prevented the problem , but honestly, If I am adding something that in any way degrades the reliability of the gun then I am not interested. I just wanted to share that with the group.