Amazon has AUKEY's very popular USB-C PD battery pack on sale today, it's priced at just $56 when you use the promo code FORMOMP7 at checkout. That brings the price down from its original price of $76.99. Effectively taking $21 off of the regular price, and making it more than worthwhile to pick up.
The AUKEY USB-C Power Delivery Battery Pack has a USB-C port available, as well as two USB-A ports. The USB-C port is used for both input and output, but it is also able to charge something like a Nintendo Switch or a USB-C laptop at full speed. Which is definitely a good thing here. Now if you don't want to use the USB-C port, there is also a micro USB port available for charging the battery pack. The other two USB-A ports include a Quick Charge 3.0-compatible port and a AiO Power port, which is AUKEY's proprietary quick charging standard that will charge your phone as quickly as it can without damaging the device. Basically, this battery pack is able to do everything for you, and it has a capacity of around 30,000mAh, so it's going to keep you going all day long and then some. Definitely worth picking up if you do a lot of traveling, or even if you go out camping, since there is a flashlight built-in here.
This item is also eligible for Amazon Prime's free shipping. Which includes free two-day shipping, and pretty cheap (usually $3.99) next-day shipping if you need it extra fast. If you are not an Amazon Prime member yet, you can sign up for a free trial of Amazon Prime. You'll get 30 days free (if you're a student, you get 6 months), and then it's $99/year (or $49/year for students). Prime members do get a whole lot more than just free shipping though, so be sure to check out the full benefits.