"Artillery Level Repulsor Technology Suit with Reinforced Chest RT and Armor Stabilization Dampers. It is also equipped with adjustable Power Level Repulsors."
?(Iron Man 3 - JARVIS: A Second Screen Experience) The Mark XVII's description in the JARVIS Application.

The Mark XVII (Mark 17), famously known by its name as the "Heartbreaker", is an Artillery Level RT Suit, and was one of several new Iron Man Armors created by Tony Stark as part of the Iron Legion. The armor was created sometime after the Battle of New York.[1]

It was featured in Iron Man 3, and made its debut when Tony ordered J.A.R.V.I.S. to initiate the "House Party Protocol", in which it was activated along with all the other suits to aid Tony in his battle against Aldrich Killian.

The suit earned its name the "Heartbreaker", because it has an oversized chest RT, which can fire powerful blasts. The Mark XVII can fire narrow or wide beams and can also generate a Repulsor Shield for protection