【無料】
❶at no additional charge (追加費用なし) - You can get this complementary gift at no additional charge to you.
❷at no additional cost - Here is an extra bag at no additional cost.
❸at no extra cost - At no extra cost, we've included another item for you.
❹for free - Please take one of our brochures. They are for free.
❺free of charge - I'll let you have another coffee. Free of charge.

☆Please feel free to〜 If you have any questions, please feel free to ask.
= 自由に〜してください