At the request of the customer, please send me the specification of AC cable that I have ordered this time, thank you. For reference, I will attach a sample of the specification that the customer sent to me.
I have requested by a customer for the specification sheet of AC cable, so please send it to me. I attach a sample specification sheet received from the customer for your reference.
... I will attach a sample... → ... I will attach the sample...
上記のように訂正させてください。