• This fitted cot sheet lays smooth beneath your little one; even through tosses and turns. Crafted from soft and breathable premium cotton jersey, it's perfect for all year round. Created to stretch yet retain its shape, this fitted sheet also comes fully elasticized, which means there's no pulling off or bunching. Our fitted sheets fit both standard and large size cots including Boori, Grotime, Tasman Eco, and more.