For myself, I use it to connect the extension cord to my heated waterer cord, so extension cord from the outlet, then I use this between the cord and the waterer cord (the waterer cord does not reach the outlet), so the chickens do not throw water on it, (not between extension cords). So only 1 extension cord, but it is way better than duct tape (like the original poster mentioned) if you do need to connect cords. All electric connections in the coop should be covered if possible.I have used that cord lock when connecting cords. However, IMO the safest is to have a single cord, without having to connect a second one. Spend the money to buy one that's long enough to do the job if that's an option.