[Translation from Japanese to English ] I received "Tour Issue TP MB iron set." I have a question about "Txxxx ser...

Original text

"Tour Issue TP MB iron set"が届きました。

"Txxxx serial"について質問があります。

3-9番アイアンまでは、"Txxx"となっていますが
PWのみ、"STxxx"となっています。

なぜPWのみ"S"から始まっているのですか？
PWは"Tour Issue"ですか？

回答をお待ちしています。

Translation / English

I received "Tour Issue TP MB iron set."

I have a question about "Txxxx serial."

Theres's form 3 to 9-iron as "Txxx."

But, only PW is as "STxxx."

Why PW starts from the letter "S?"

Is a PW "Tour Issue?"

I look forward to your reply.

Translation / English

I have received "Tour Issue TP MB iron set."

I have a question regarding "Txxxx serial"

For No. 3 - 9 iron, it shows as "Txxx" but PW only, it shows as "STxxx."
Please explain why PW is shown with an "S" prefix. Is PW a "Tour Issue"?

Looking forward to your response.

Translation / English

I have just received "Tour Issue TP MB iron set.
I would like to ask something about "Txxxx serial.
Untill 3-9 iron, the number is "Txxx", but only PW, it is "STxxx".
Why only PW starts from S?
Is PW Tour issue?

Thank you