The Modular Expandable Armor System (MEXAS) is a composite armour system developed by the German company IBD Deisenroth Engineering. MEXAS was introduced in 1994 and has been applied on over 20,000 combat vehicles worldwide. The successor of MEXAS is the Advanced Modular Armor Protection (AMAP). Design The Modular Expandable Armor System (MEXAS) was developed in the early 1990s by IBD Deisenroth and first used in 1994. In 2005 it was succeeded by the next-generation AMAP armour system, which provides a wider variety of different armour options. MEXAS has been marketed in three versions: MEXAS-L (light) offers protection against small-calibre rounds and can also be fitted on soft-skinned vehicles like MAN military trucks. MEXAS-M (medium) protects the vehicle against autocannon and RPGs with HEAT warheads. MEXAS-H is for use on heavy vehicles like main battle tanks. Depending on version and required protection level MEXAS can protect against kinetic energy penetrators like 30 mm AP, RPGs and mines like the TM-46 mine and TMRP-6 In order to reach different types of desired armour protection MEXAS is either passive armour or non-explosive reactive armour. The exact composition of MEXAS is classified, but according to drawings from the manufacturer the passive version of MEXAS consist of a splinter foil-like specialized Nylon covering a layer of ceramic tiles (possibly materials like aluminium oxide, silicon carbide and boron carbide depending on the user's requirements). Behind the ceramic tiles a layer of aramid backing (e.g. kevlar) is installed. MEXAS also includes spall-liner and depending on the user's requirements a mine-protection kit. The reactive armour version of MEXAS utilizes several spaced multilayer plates consisting of an inert interlayer sandwiched between metal plates. During penetratíon by a shaped charge jet, the sandwich bulges similar to explosive reactive armour (ERA) due to the interlayer absorbing the jet momentum and spreading it radially. Such armour provides better coverage than ERA (up to 85–95% of the surface compared to 30–60%), can be mounted on vehicles with very limited base armour that would not sustain the blast of an ERA tile without damage and has a lower life-cycle cost. MEXAS is only used as adaptable applique armour and is usually not the only protection of a vehicle, but overlaid on the vehicle hull made of ballistic aluminium or armour steel. During the development of Bionix AFV MEXAS composite armour was adapted to the vehicle. To meet the required protection against heavy machine gun