for 3 degus you need a large cage i cant see how large it is but it did not look large they are rodents yes but they require mutch more space than the average rodent
Please remove any and all plastic from your cage. Unlike rats, degus do not have a mechanism that prevents them from swallowing things they chew on. Due to this, little plastic parts are often swallowed and can cause internal damage which quickly leads to death. I would recommend a wooden wheel (minimum 30cm so that their spines do not get damaged).
The biggest problem here in Japan and that the cages are small due to lack of space in the houses here are larger cages for rabbits and ferrets, and that was the biggest I've found for degus ToT . His cage was you who built it? I found very nice!