CUB 2mm Steamer CUB wetsuits are made with super soft, superstretch neoprene which has the flexibility to fit kids of all different shapes and sizes. As a general rule we recommend choosing size based on clothing size. Features 2mm superstretch, non-petroleum based neoprene. Nylon internal jersey for extra softness and comfort. AquaTM water based solvent used during lamination Flatlock stitching for durability YKK Backzip for easy cub access Full sun / UV protection Kneepads No lower leg zipper (After years of R&D we found the design with no lower leg zipper to be much easier to put on than with a zipper. Our material is very flexible, the zipper creates extra bulk and limits the flexibility in this part, making it harder to get on your cub's foot. Note - To assist we recommend using the compostable bag you receive your order in by placing it over your child's foot to make sliding on even easier.)