T-Mobile (TMUS) began a limited time promotion on Friday, discounting both the Apple (AAPL) iPhone 7 and iPhone 7 Plus by up to $300 for customers who trade in an iPhone 6, iPhone 6 Plus, iPhone 6s, or iPhone 6s Plus.

The Un-carrier also said that customers could combine the $300 trade-in deal with its ongoing memory upgrade offer which cuts the price of the 256GB iPhones by $100, the average price for the 128GB models.

All storage configurations and colorways are eligible, T-Mobile said.

Shares of T-Mobile were slightly lower early Friday afternoon.

Apple is a holding in Jim Cramer's Action Alerts PLUS Charitable Trust Portfolio . Want to be alerted before Cramer buys or sells Apple? Learn more now.

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