The antennas on the small backpack are permanently attached.
Both backpacks plug firmly into the back of the droid.
This class has 200 health points, high durability, low mobility, and is equipped with powerful blasters and shields.
The regular backpack has a hole on the side where the blaster can be plugged in, this way the Battle Droid can carry it around without holding it in its hands The Heavy class has the highest health of all four soldier classes, allowing it to absorb and deal immense damage at the cost of having decreased mobility as well as a slightly slower regen.
The Droid blaster fits very well into the Battle Droid's right hand, and only loosely into the left hand.
Besides the two different backpacks and Droid Blaster, Hasbro also included additional weapons such as the Heavy Repating Cannon (first seen with the First Order Stormtrooper with Extra Gear) and the basic long Blaster Rifle which was first included with the 2013 Black Series Sandtrooper figure.
The figure is a repaint of the basic Black Series Battle Droid from 2019.
This Heavy Battle Droid was released in February 2020 exclusively at Gamestop/ThinkGeek stores under the Black Series Gaming Greats banner.