You take off the black covers and the mesh comes with Velcro so you just carefully cut it to size and attach. It does say on the cover do not block the vents but the mesh is very light and enough air will be able to circulate IMO but only advice so take it with a grain of salt. Don't know long term effects to limiting air flow a bit. I have seen on this forum where people put mods behind the fridge by adding additional fans to push air around so there may be need for that down the road. This is my first trailer and I have not yet experienced a faulty fridge. I have learned a lot of to do's and what not to do's on this forum. It pretty awesome cause I enjoy my trailer and I love tinkering around on it doing cool mods and upgrades.
FYI - I have had no problems with the sidewinder but again I have not had to stretch it out very long yet and it says it goes to 20' but I do agree with need-a-vacation that it is a little of a pain in the arse to get the tube to lay just right and I use fire wood to put in a downward flow. I like the idea of the gutter but I bought my trailer and most of this stuff before I came across this forum. Wish I came here first to learn all I know now from the veterans of this new hobby