Standard Cot/Cotbed Foam Safety Mattress What size mattress do I need? Getting the right size and shape is essential as little limbs can easily get caught in gaps at the sides and ends of the cots. That’s why we always recommend that any gap should be no more than 3 cm. We have mattresses to perfectly fit all our nursery furniture from a moses basket up to single beds, as well as special sizes for items outside of our standard range.  How to measure. To measure the size of the mattress you need, measure the internal length and internal width of the furniture in cm. Features: Thicker 10cm foam inner (Depth) - made from hypo-allergenic CMHR25 density safety foam as required by British Standards. This filling contains no antimony, phosphorus or arsenic. Mattress Covering is PVC & Mesh - Two thirds non-toxic, waterproof PVC & one third breathable tricot mesh. Please note that the PVC is not breathable. Top third of the mattress is breathable tricot mesh. Ventilation holes at the Mesh head section which encourages airflow throughout the mattress. Bottom two thirds of the mattress is covered in a non-toxic PVC material. Meaning it\'s easily wiped down with soapy water or disinfectant, keeping the mattress free from contamination. Manufactured without the use of antimony, phosphorous, arsenic, barium, lead or other nasty fire retardant chemicals. Complies with the rigorous requirements of BS 1877 part 10 for safety and performance and BS 7177 for flammability. Please note: We want you to be happy with your purchase and recommend you check the fit of your mattress before opening and/or removing the packaging. We are unable to accept mattresses back for exchange or refund once the packaging has been opened. This does not affect your statuary rights.