GRD-KNOB 3 1/2" Guard Knob for Gates
It’s role is to help prevent people from reaching their hand to the inside of the gate to activate the walk to open up the gate
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The screw holes are 3-1/2" and 2-1/2" CTC
I believe you can make this work.
Our return policy page is posted on our website but in short it says there would be a 35% restock fee on this and the hardware must be in brand new mint unused uninstalled condition.
Regarding a drill bit, yes it is indeed something that we can supply so your installer would likely have an abundance of drill bits, plus you mentioned when we spoke that you were going to weld this to the gate.