c&c ramp

... but I'm not a native English speaker. What's the name of the black plastic "things" the person is using to cover the sides of the ramp in this video please? I'd like to order something like this from Ebay or Amazon, but I'm not sure what search term I need to use. Thanks in advance! :)

At the end of the month I'm donating money to a local rescue and getting some c&c grids and connectors. Currently I have a 2x5 that houses my 2 girls and a spare cage for my boar. I'm wanting to make an L shaped c&c with a loft and also dividing part so my boar isn't able to get in to the...