T-Mobile, the country's third most-subscribed carrier, has just announced an interesting weekend promotion designed to boost Samsung Galaxy S6 sales. The deal starts on Oct. 22 and will expire on Monday, Oct. 26.

As prefixed on the magenta carrier's official web page, interested takers can get both a 32GB Galaxy S6 and an eight-inch Galaxy Tab A for $0 upfront and $0 per month.

The catch? Well, there are quite a few, actually.  First off, to get the freebies, you need to have one of the following 2014 to 2015 flagship smartphones:

  • iPhone 6
  • iPhone 6 Plus
  • iPhone 6s
  • iPhone 6s Plus
  • Samsung Galaxy S6
  • Samsung Galaxy S6 edge
  • Samsung Galaxy S6 edge+
  • Samsung Galaxy S5
  • Samsung Note5
  • Samsung Note 4
  • Samsung Note edge

Only if you trade in one of the aforementioned devices will you be able to acquire a brand-new Galaxy S6 for free.

One unsurprising caveat is that you'll need to subscribe to a wireless service from T-Mobile. Basically, the company is leasing the smartphone to you. In the event you cancel the service within the 18-month period, you'll have to return the Galaxy S6 or pay it off to keep it.

If you're using an older flagship, you can still get the Galaxy S6 but it will cost you $15 per month for 18 months. If you're fine with the deal, you need to bring in one of these smartphones:

  • Samsung Galaxy S4
  • HTC One M8
  • HTC One M9
  • iPhone 5s
  • iPhone 5c
  • LG G3
  • LG G4

If you don't have an eligible trade-in device but still want the Galaxy S6, T-Mobile has the device on lease via the Jump! On Demand program for $24 per month. This means that the trade-in value of the secondhand smartphones is only $162.

Those who lease the Galaxy S6 through T-Mobile's promotion need only to attach a qualifying data plan to their account in order to pick up a Galaxy Tab A for free, PhoneDog reported.

T-Mobile's weekend offer is ideal for those who own a Galaxy S5 from last year and would like to swap it for this year's model sans the additional cost.

Specs for the Galaxy S6 include a five-inch 1440 x 2560 touchscreen display with 577 ppi pixel density, Samsung's quad-core Exynos 7420 processor clocked at 1.GHz, the Mali-T760MP8 GPU, 3GB of RAM with 32GB of storage space and a non-removable 2,550 mAh battery, as per Phone Arena.

The device sports a 16-megapixel main camera with support for LED flash, autofocus, touch focus and optical image stabilization. Meanwhile, its five-megapixel front-facing unit is capable of Auto HDR and dual video call, all of these running on Android 5.1.1.