Wedge

From fattwiki

The Wedge is a Zenith Fund model mech. They are Kathekons recolored in the dark blue and gold of Stel Columnar, and maintained with much higher quality (and experimental) materials. Unlike the Kathekon for Apostolos, the Wedge does make up the bulk of the “frontline” hollow squads, and provide security for more vulnerable hollows (and support for more powerful ones). These have flexible armaments.

In the case of the Wedges seen in "Ambush in the Sand": One wields a flamethrower and an electro-net launcher and one has a heavy machinegun. Both have weaponized, hollow sized chainsaws, as well.