Please note that this is not an invoice, it is an Order Acknowledgement.
I have check this as per your request in your e-mail below, I can't see a discrepancy on the OA.
The only thing different is that item number 6 is not on this OA as this will be placed onto our system by our Calibration House and you should receive an Order Acknowledgement from them.
If you would like me to make changes, would you please advise