This breathable, waterproof mattress with 360 degrees of airflow has two stages of firmness—a firmer side for infants and a medium-firm side for growing toddlers.What it does: The breathable cover features a soft organic cotton surface and a three-dimensional polyester lattice structure that allows air to flow through the fabric and under the baby for 360-degree air circulation. Since air is able to pass freely through the cover’s 3D structure, babies can breathe right through it.Additional features: The breathable function is encapsulated in a washable cover that completely hugs the mattress. In the event of an accident, remove the soiled cover and wipe the mattress clean. Replace with a spare cover or put the baby back to sleep on the fully functional underlying mattress. The cover can then be machine washed and dried at your convenience.Includes: 2-stage mattress and removable coverSizing information: 19 lb.; 27.25" x 51.63" x 6" 144-coil innerspring 13.5 guage coils with 8-guage border provide stability and durability Formaldehyde-free Removable cover is machine washable Polyester/organic cotton Wipe clean Made in the USA