An attic inlet has a square tube to communicate between an attic and a room through a substrate, with a lid permitting airflow when open, and not when closed. The lid is moved by upper pull bars and lower connecting bars attached to the lid. Upper pull bars and lower connecting bars are attached by pivot pins to yoke arms pivoting about parallel axles. Springs may urge the lid into closed default position. An axle with an associated stub arm may be rotated by cord to open the lid. Alternatively a counterweighted arm may urge the lid into closed default position, where negative pressure can open the lid. The lid is attached by tabs on the connecting bars passing through the lid, and lid locking bars engaging apertures in the tabs.