Interest Free (Grace) Period A length of time the user of a credit card is entitled to credit without having to pay interest assuming prompt monthly payment.

免息期/宽限期 如果每月及时还款，信用卡持有人有权免息使用一定信用额度的期间。

youdao

Grace Flint has a microphone the size of a shirt button, connected to a transmitter as thin as a credit card, that will relay any foolish admissions you might make to her from around the corner, or across the city, or from just about any place on earth.

CNN: Books - Excerpt: 'Flint'