Putting in a new counter top, on a built in desk. Walls on back
and sides. Old top had a large hole to run wires down to the
computer, power, etc. I would like to leave the top approx. 1 ½
inches away from back wall to easily drop wires down. I’m
looking for some suggestions on a material to fill that gap?
Something like foam or rubber that could easily be slit, and a
wire could be fed thru it. Any suggestions?

Thanks
TP