Hi Tizzie. Can you tell me what is an acceptable gap between rails and mattress? I just purchased a tasman cot with their mattress which is 1300mm x 750mm and there is a 34mm gap in the width. This seems huge to me if l compare to the Boori cots and mattress tbat really dont have any gap. If l get a larger mattress then it will be bigger than the base of cot… trying to get my money back. Cannot understand how it was made this way. It is a shame as it is a beautiful mattress. Your advice would be greatly appreciated. Kind regards.