This trap comes assembled with a convenient release door located on the side of the trap. This door provides easy access to the trapped sparrows. Also has 2 repeating trap doors. This Sparrow Trap can hold up to 20 sparrows at a time. The mesh size is 1/2 in x 1 in 16 gauge wire. The trap size is 24 in L x 12 in W x 8 in H.