RM-MS-22 "Sand Stork" Zaku II: The RM-MS-22 is a copied and modified version of the MS series of Zaku II's, instead being used used by Raptor Machina as their main frontline mobile suit. This 22 version is meant for desert operations and is thus equiped with some modifications. Its feet are modified to better stand on sand so it doesn't sink and for higher mobility the feet can also expel a cushion of air thanks to extra motors allowing it to hover right over the ground's surface much like an old earth hovercraft. It waist has extra armor plates and protection to cover the joints and other critical parts from enemy fire and damage that may come from the harsh enviroment. The shoulders are also larger as they hold extra cooling equipment, radiators and extra protection against wear and tear from the elements. The head is a miniaturized and modified "Dom" head meant to house better optics and long range sensors. The mounted thrusters on the mobile suit are also specialized for low altitude flight, speed and reliability which makes high altitude and rapid manouvers inefficient coupled with all the added weight. Combined this makes this desert variant unsuited for close range combat and instead rather excel at long range combat utalizing its advanced optics and speed at low altitudes to quickly set up ambush positions and to keep distance from itself and enemy units who will often outnumber it.
RM-MS-64 "Beetle" Zaku II: The RM-MS-64 is a frame specifically designed for close range combat and breaching tactics. The main frame is built using rare materials to give it improved protection while still keeping the chest frame small for better agility and weight, vital for close range combat. Its legs are also built for short bursts of high speed coupled with its powerful thrusters allows it to blitz enemy targets and with the arms having higher freedoms of movement thanks to the smaller chest it can easily destroy its opponents. A prefered melee focused configuration for the RM-MS-64 is a MK-III 'Eagle' Thermal axe in one hand and on the other a large DRUP-B99 Heavy shield is often used which also attaches to the frame's shoulder. The shield offers superb protection and missile grenades can be mounted under the shield which then can quickly be fired from their racks for longer range engaments and to soften up enemy positions.
RM-MS-08 "Void Knight" Zaku II: The 08 is mainly used in space because of the HH-9Y6 Thruster-Backpack that was specifically designed for this variant giving it massively improved speed and agility in space, coupled with its own improved leg thrusters. The most protected parts of the mech are its feet, chest and head as it focuses on its speed to make sure it stays alive. It can carry a wide array of weapons like assault rifles, machine guns, rail rifles and many more, except rocket shouldered weapons like Bazookas because they are too large and get in the way of the thruster backpack. The "Void Knight" is a difficult frame to pilot because of its ludicrous speed which also puts it on the higher side of maintenance costs because of the faster wear and tear caused by added frame stress and random debree.
RM-MS-03 "Fulcrum" Zaku II: The Fulcrum is the standard issued, mass produced frame mainly meant for land combat but can work basically anywhere else. It is cheap to produce, easy to pilot and easily maintained by ground crews. It offers moderate protection to the vital parts on the base frame but extra armor kits can easily be mounted if requested. It offers flexible thrusters to quickly manouver around. They aren't anything fancy like some other frames' but they work in any situation, being good at everything, but masters of none. It also often comes mounted with smoke launchers which can quickly be deployed to conceal the frame if needed for a short time. Only drawback of the frame being that while cheap, cheaper than most other frames trying to fill the role, the construction does take a little longer than average and some parts, mainly the arms, are complicated to build and mount. So the production run takes longer than usual but the cost is very low and when it is completed it is even cheaper and easier to maintain while also offering a wide range of capabilities. The construction issues can possibly be fixed if extra funding is diverted to the manufacturer.