gate latch

I'm struggling to find a solution to keeping my garden gate open, have Googled lots of ways bit not found anything that will work. Hopefully someone on here will have an idea. I kind of know what I want, something that will fix to the wall and hold a metal framed gate with composite boards open...

Hi, I've over engineered a gate that's about 100mm thick - does anyone make a long throw lock that might fit? I can't find one using Google. I don't want to use a bolt and padlock if I can avoid it, Thanks John

The screws in this work loose and it falls off !