Question about Thermaltake Riser Card PCIe Extender Cable

How long is the cable really? I would like to replace my "Rajintek Riser cable (250mm length) - RJK PCIe 16x Gen3" (installed in the Rajintek Ophion EVO) and need a cable with at least 25cm cable length or with such a stiffer cable it should be more like 26cm. Another manufacturer's specification was already wrong and the "30cm" cable was too short to replace my 25cm cable. Does Thermaltek measure the cable length with the 30cm or the total length? Is it rather shorter or is the specification correct?