On your iPhone, iPad, or iPod touch
1. On your device open iTunes Store App.
2. Scroll to the bottom of the Featured section and tap Redeem.
3. Log in with your Apple ID.
4. Tap "You can also enter your code manually."
5. Enter the 16-digit code, which starts with X.
6. Tap Redeem. After redemption is successful, your iTunes account balance automatically updates.
On your Mac
1. Launch iTunes.
2. Click Sign In. Then enter your Apple ID and password.
3. Click your name. Choose Redeem from the menu.
4. Enter your password again.
5. Enter the 16-digit code, which starts with X
6. Click Redeem. After redemption is successful, your iTunes account balance automatically updates.
You will be able to see your updated balance in your Chinese iTunes Store account once the iTunes Gift Card is redeemed.
Credit will be deducted from your iTunes Store account each time you make a purchase until the funds are depleted.
You can use it across all your devices, so go ahead and redeem it today!