We have added some unique Grade 3 contacts to our Heavy Duty range in the last few years. Our YF10C is universal (not handed) and has selectable resistors incorporated inside the housing which will suit most main control panels. Our YH10A does the same but in the housing of an angle contact. Both have decent operating gaps. The YM10 is a superb G3 option. It is housed in a large aluminium case with a removable cover and micro-switch tamper and, like the YH10A and YF10C, has magnetic interference detection but gives you eight easy fit brass terminals to which to connect.