Kolcraft Pure Sleep Therapeutic 150 Crib Mattress

Amazon.com Price:  $59.49 (as of 18/10/2017 13:33 PST- Details)

150 heavy gauge steel coils for firm support while your baby sleeps and grows
Waterproof cover and lock-stitched waterproof binding resists stains, moisture and mildew – entire mattress wipes clean with a damp cloth for a sanitary sleeping surface
GREENGUARD® Children & Schools certified for indoor air quality and low chemical emissions to help create a healthier sleeping environment for your baby.