This is the extendable Classic Mattress for the Sebra Baby and Junior Cot Bed.
Each mattress comes in two parts, one that fits the cot and an additional panel to extend the mattress when the bed is turned into the junior size.
PLEASE NOTE THIS MATTRESS HAS NOW BEEN DISCONTINUED AND IS REPLACED BY A NEW VERSION :
https://ellajames.co.uk/products/classic-ll-mattress-for-sebra-baby-and-jr-cot-bed