https://www.cnet.com/news/nintendo-labo-replacement-kits-cardboard/

Nintendo Labo is a novel series of accessories that work with the portable Nintendo Switch video game console. Requiring assembly and made out of cardboard, these kits are aimed for kids and can transform your Switch into a robot backpack, piano, motorbike and more. 

But because these kits are made out of cardboard, they aren't the most durable accessories. As such, Nintendo is selling replacements parts online.