A: The dimensions listed are a very common cut for A5. The reason they do not match the definition of A5 as listed in a paper size chart is this: When cutting paper down from the A0 size that manufacturers buy it in, there is always some trim as it goes through the equipment. While we could produce a refill that is exactly the international definition of A5 (and did at one time), the waste from the trimming process is considerable. Waste drives up the manufacturing price and it's, well, wasteful. This is why we list the detailed dimensions -- to help people who are mixing and matching covers with refills avoid an awkward combination. This is also why we provide our own refills... so people will know for sure that the refill fits. See also our SohoSpark Compatible Refills.