Plastic. I use them for VR gaming and theyre great. Keep you finish like glass. The white goes with everything. I like that the crisscrossed straps make them look less mary jane-ish. You can put three more on the top rack for a total of nine. - The RGB looks great! Mounted it vertically instead of horizontally. I really like the style of this walking shoe and I love the crossover stretch band instead of laces. My only advice is to SIZE UP, but then again I also have a boy with bigger feet than average which could be making me say that .