These square play yard fits joovy sheets are made of the finest '100% cotton jersey knit` material. Sheets are made with deep pockets and are elasticized around the entire edge which prevents it from slipping off the mattress, thereby keeping your baby safe. These sheets are so durable that they will last all through your baby's growing years. We're called SheetWorld because we produce the highest grade sheets on the market today. Features the one and only Princess characters! Fits standard square play yard fits joovy mattresses measuring 38 x 38 inches.