Modular Reinforced Insulated Sheath Armor, also known as RIS armor or the MRIS system, is an advanced type of lightweight modular unpowered body armor geared towards special operations and noncombatant personnel. It typically consists of three layers: a heavy Class 1M-rated primary layer, a Class 1K-rated secondary layer, and a Class 1D-rated tertiary jumpsuit.
Protection
The MRIS system provides protection by means of interchangeable, removable layers. These typically consist of modular interference-resistant magnetically-connected armor plates, which are hooked up manually to the jumpsuit by means of heavy-duty load-carrying loops. Despite it's low weight and focus on mobility, it provides a high degree of personal protection, especially when the layers are in tandem with one another.
Primary Layer
The primary layer is typically the thickest, and is Class 1M-rated at the minimum. These plates are usually rigid, hard SAPI or Shooter's cut armor plates with a spall liner, with the most common variety consisting of a heavy tritanium alloy plate that covers the front and back of the wearer. While tough, the primary armor layer only usually covers the most essential vital organs, the lungs and heart, due to the restrictive weight of larger 1M-rated plates, although in tandem with the two other layers, there is little to nothing that can penetrate a wearer's vital regions.
A chest-mounted light can be attached to the middle of the primary plate, configured for low-light red, IR, strobe, or white light for various mission needs. The MRIS chest rig's straps can be configured to go over the primary layer without difficulty, provided that the wearer adjusts for the thickness of the plate compared to the secondary layer.
Secondary Layer
The secondary layer protects most of the chest region, although it's rated lower on the protection scale at Class 1K instead of 1M. It is more flexible than the primary layer, consisting of smaller spaced plates with cuts for maximum mobility and ease of access, and is designed to provide the highest degree of lightweight protection against small arms fire that can be afforded to non-vital areas. For low-profile or non-combat personnel, the secondary layer often replaces the primary layer in terms of protection.
Tertiary Layer
Forming the backbone of the MRIS system is the tertiary layer, which consists of a fully-sealed, pressurized, fire-retardant, Class 1D-reinforced armored jumpsuit made of synthetic cloth and tritanium mesh weave to spoof sensors. Typically, it is in uniform black, with provisions on the chest to mount heavier armored plates. A belt keeps the jumpsuit well-fit, and can accommodate personal shield generators or ammunition pouches.
Additional Equipment
Chest Rig
MRIS armor sets are shipped with a low-profile chest rig with provisions to attach modular pouches depending on mission requirements. These sit comfortably below the primary layer, and allow easy access of equipment, grenades, or reloads in combat conditions. It is made of synthetic fabric and can be reinforced with a soft armor layer or additional armor plates.
Adaptive Active Thermal Camouflage Poncho
Special operations forces are typically outfitted with full-body loose-fitting ponchos with hoods and masks, which consist of hundreds of 5.5cm hexagonal Peltier plates over an insulated plastic layer and powered by a belt-mounted power pack. These plates can heat and cool rapidly to mask the thermal signature of the wearer by blending in with the background or mimicking the appearance of something else. Externally, the plates can be colored in many different patterns, with the hexagonal pattern proving to be a competent option for disruptive camouflage.
Personal Modifications
Many operatives have modified their MRIS systems to suit mission and personal preferences, with the modular nature of the system playing well into these changes. The most common is homebrew camouflage, consisting of printed cloth or spray paint. These are typically in splinter or stripe patterns for maximum disruptive potential, breaking up the shape of the wearer depending on the environment. Armor plates can be shaped or fabricated to fit the arms and legs, the most notable being the "machine gunner's cut", where Class 1K layers are specially cut for arm armor. These flat plates strapped to the forearm and bicep are common among MRIS wearers, although Type 19 and Type 21 operators wear a specialized version with longer plates to protect not only their arm, but the more sensitive parts of the gun. This has been obsoleted by the addition of a small gun shield to the left side of both weapons, but machine gunners are often found wearing their old sets.