Product Overview: 3" W & 5-1/2" H Universal sparrow trap with screws. To maintain functionality, it is recommended that slot openings do not exceed 3-1/2 inches in width. Modifications to the box design may be needed if wider slots are used Compatible Models: Fit for nest boxes with multiple entrance types use on front, back, and side opening nest boxes, fit nest boxes with round, oval and slot entrances Product Function: Efficient elimination of non-native house sparrows so bluebirds/ tree swallows/ chickadees/ etc, can nest in peace, providing reliable performance season after season Great Material: Made with quality materials, structural solidity, not easily broken or damaged, this sparrow trap is built to withstand frequent use and harsh outdoor conditions Easy to install: Easily mounts to nest box with included screws, in the tripped position, the trap dimensions are 3" (76 mm) in width and 5.5" (140 mm) in height to maximize sparrow capture efficiency. When set, the tripper wire extends rearward by 3" (76 mm) to ensure reliable engagement 3" W & 5-1/2" H Universal Sparrow Trap with Screws Fit for Nest Boxes with Multiple Entrance Types, Fit Nest Boxes with Round, Oval and Slot Entrances, Use on Front, Back, and Side Opening Nest Boxes