I’m looking for a mattress that will fit the childcare cosy time co sleeper bassinet

Hi Hayley, thank you for your enquiry the internal measurements for the Childcare Cosy Time Sleeper is 810mm (L), 520mm (W) & 300mm (H). The Baby First Bassinet is smaller so may not be suitable however, there are two others that are closer in size to the Cosy time sleeper:
https://www.babyonthemove.co.nz/baby-nursery/mattresses/bassinet-mattress/foam-fibre-round-end-bassinet-mattress
https://www.babyonthemove.co.nz/baby-nursery/mattresses/bassinet-mattress/round-bonded-wool-foam-core
?For further information on this or any of our other products available, if you follow the link https://www.babyonthemove.co.nz/store-locations/ this will take you to our online store finder. Here you can find contact details for your nearest Baby On The Move Store where one of our team experts will be happy to assist you in your product search and help answer any further questions you may have. We hope this has helped with your query.