The Lumia 550 is the "other" Lumia device that was announced alongside the Lumia 950 and 950XL. The Lumia 550 didn't gain much traction as it was out-shined by the 950 and 950XL.
The Lumia 550 has a 4.7-inch 720 display, a 1.1 GHz quad-core Snapdragon processor, 1GB of RAM, 8GB of storage, a 5-megapixel rear camera and a 2-megapixel front camera. Microsoft promises up to 10 hours of Wi-Fi browsing or 14 hours of 3G talk time from the 2,100 mAh battery, which is removable.
The Lumia 550 is actually a very decent budget friendly Lumia phone all for a price of $139.
There is no continuum support, neither is there Windows Hello (iris scanner) butt hat's what you get at that price point.
If you are any where in Europe and are interested in the Lumia 550, you can check with your local Microsoft store for availability