I tend to agree with OTC that to use "blind" tunnels does reduce the catching options somewhat, i prefer mine open at either end also. That said, I like the wire restricted entrance........lets more light into the unit if you are using bait at one end. If i use my double entry tunnels at a tree bases.......i just push one end into the tree base to leave the other end open, squirrels will enter the tunnel out of curiosity without any need for baiting, and find the Mk 4 sitting ready and waiting.
Rolfe.