From Halopedia, the Halo wiki
The Hazops Cyclops, also known as the Zombie Containment Cyclops, is a specialised variant of the HRUNTING Mark III (B) Cyclops, employed by the UNSC Marine Corps and Spartans, presumably those of Flood containment Fireteams.
The Zombie Containment Cyclops is equipped with an arm mounted directed-energy weapon. The Hazops Cyclops are equipped with biolab-grade environmental sealing and a heavy flamethrower and are sometimes assigned as support vehicles to Spartan assessment and containment teams at Forerunner sites which may house Flood samples. Unfortunately, it is often necessary to destroy these suits at the end of successful containment missions, as properly cleaning every nook and crevice for traces of Flood spores is prohibitively challenging. A worst-case scenario - so far explored only in simulations - is one in which the operator is infected by the Flood and FSC-based biomass further augments the existing exoskeleton armature.
The Hazops was first visualized by MEGA Brands Halo Toys as the "Zombie Containment Cyclops", and the described simulation-only Flood-augmented Cyclops as the "Flood infected cyclops". The vehicle was considered a separate entity to the Mark III described on Halo Waypoint until February 2020, when Jeff Easterling confirmed the connection.