use the following link: https://secure.f5.com/validate/validate.jsp
It will provide information from the vendor as to what support they say is on the box and when it is valid until. It may not be 100 percent correct, esp if there was a mixup. But it’s a start.
You can use this in conjunction with checking that serial with Opmin to try and verify what, if any, support is on an F5 customer host.