this sight is full metal as it says it is in the title
also this red dot scope will fit most guns as long as your gun has a RIS or weaver rails, also most rails are 20mm in size because that is the normal, so if your gun has rails then this will fit it
also make sure that your gun hyas rails on top of the gun because you dont want to put this scope on a bottom rail
bottom rails are for flashlights, lasers, and foregrips, etc...
hope that helps