Support engine version: 4.3.0 or higher.

You can get the latest update of this pack for free here.

The pack is a part of Mech Constructor series, and can be expanded by
The Light and Meduim Mechs, The Spiders and Tanks, The Humanoid Robots,
and other assets. The textures match, and the parts are intechangeable.

The pack contains over 70 prefabs of different modules, that will allow you to create numerous combinations of turrets and towers.
The buildings are extremely easy to assemble - just drop the parts into the corresponding containers and they'll snap right into place.
The poly count of units varies from 500 to 3000 tris.
The textures include a hand painted 4k diffuse atlas (in multiple colors), which looks good even unlit, and a set of PBR maps. Version: 2.1