What Jack said. Also, I have'nt looked for one myself, but I'm curious if they have after market vent covers with some easy way to insert a "shade" , or dark filter, for when you don't want light. I know I'm suppose to enjoy getting up at the crack of dawn but, often, I really don't---and in the summer the morning sunshine likes to come through that thing and lighten up my sleeping area more than I appreciate. Just a thought. 
Rick
Rick
