3 position adjustable mattress base - allows you to lower the height of the mattress as your baby learns to sit and stand. Drop side - this allows you to lower the rails so its easier to lift your baby in and out. Teething rails - protects your babys gums once they are teething and have started to chew. Cot specifications: Size L125, W69, H97cm. Mattress features: Mattress size L120cm, W60, D60. Mattress not included. General information: Suitable from birth to 4 years. Self-assembly.