Abstract: A cover 10 for an outlet O of a vertically-oriented exhaust stack S is provided. The cover 10 includes a cylindrical sleeve 20 with a convex cap portion 30. The cap portion 30 includes a lip 35 to provide a means to grasp the cover 10 during installation or removal. An inverted circumferential ridge 40 depends from the lip 35 to form a channel 50 and provide a latching profile to mate with a separate latching lug 60. The latching lug 60 is attached to a distal end 84 of a telescoping pole 80. With the latching lug 60 engaged with the ridge 40 and channel 50, the telescoping pole 80 is extended to raise the cover 10 over the top the outlet of an exhaust stack S. The cover 10 is then lowered onto the exhaust stack S and the latching lug 60 disengaged. Once installed, the cover 10 prevents entry of unwanted matter or debris into the exhaust outlet O of the top of the exhaust stack S.