[larsen]

I've recently bought a pair of what I believe are Shark silencers marked Monster 900, they have a mounting plate which attaches at the standard silencer carrier point and the silencer strap at the other end, all good, but in the middle is a smaller hole and bolt that lines up with the passenger peg upper casting. Am I correct in thinking that I am supposed to drill an appropriate hole in this casting, or am I missing something? Thanks. P.S. are these silencers any good?