A best selling mattress for cots the natural twist cot mattress from little green sheep is an award winning cot mattress that provides perfect support for your child as they grow entirely free of chemicals it fits standard sized cots and is double sided so the choice of firmness is up to you one side is firm and recommended for babies up to 18 months old or simply twist for a supple latex side that is durable and comfy for when your baby reaches the toddler stage this mattress can provide