3 position adjustable mattress base – allows you to lower the height of the mattress as your baby learns to sit and stand. Teething rails – protects your babys gums once they are teething and have started to chew. Converts to junior bed. Cot specifications: Size L144.5, W76, H88.5cm. Mattress features: Mattress size L140cm, W70, D70. Mattress not included. General information: Suitable from birth to 4 years. Self-assembly.