The TW-22LA is long 3" diameter tunnel that makes a 90 degree turn. This one makes a left hand turn and has a crescent entrance with a double width exterior porch and an interior cling rod. The inside of the tunnel is grooved to provide traction, as is the outside top of the tunnel. The TW-22LA can be used on houses, natural gourds, Supergourds, Naturelines if mounted on the rear, and Troyer's Horizontals. The TW-22LA makes it nearly impossible for a hawk or owl to reach into a gourd or house. It also helps to prevent porch domination on houses such as the T-14. This tunnel will make a gourd front heavy so that will need to be taken into consideration. The TW-22LA sells for $7.50 each plus S&H.