than MCLOS and SACLOS missiles. Examples include the German PARS 3 LR and the Israeli Spike. Most modern ATGMs have shaped charge HEAT warheads, designed specifically for penetrating tank armor. Tandem-charge missiles attempt to defeat explosive reactive armour (ERA): the small initial charge sets off the ERA while the follow-up main charge attempts to penetrate the main armor. Top-attack weapons such as the US Javelin, the Swedish Bill and the Indian Nag and MPATGM are designed to strike vehicles from above, where their armor is usually much weaker. Third generation systems and beyond are generally much more expensive than second generation systems. Fourth generation ATGMs Fourth generation fire-and-forget anti tank guided missiles have larger range and rely on a combination of seeker for guidance. Examples include India's SANT, which has a stand-off range of , uses dual seeker configuration of electro-optical thermal imager (EO/IR) and millimeter-wave active radar homing for control and guidance with lock-on before launch and lock-on after launch capabilities. Fifth generation ATGMs Some ATGMs, notably the French Akeron MP and the latest variants of the Israeli Spike (such as the Spike LR2 and ER2), have been called "5th generation" by their manufacturers and marketed as such. They appear to have the following additional or amplified attributes: passive dual-band seeker (TV and uncooled IR); multipurpose tandem warhead; smokeless propellant; less collateral damage; possible counter-active protection system (CAPS) capability; man in the loop technology; emphasis on targets other than tanks; other updates such as artificial intelligence for the missile. Countermeasures Countermeasures against ATGMs include newer armors such as spaced, perforated, composite or explosive reactive armor, jammers like the Russian Shtora, active protection systems (APS) like the Israeli Trophy and the Russian Arena, and other methods. Newer armor Armor systems have continued in development alongside ATGMs, and the most recent generations of armor are specifically tested to be effective against ATGM strikes, either by deforming the missile warhead or fusing to prevent proper detonation (such as in slat armor) or using some form of reactive armor to 'attack' the missile upon impact, disrupting the shaped charge that makes the warhead effective. Both come with the downside of significant weight and bulk. Reactive armor works best when a vehicle is specifically designed with the system integrated and while developments continue to make armor lighter, any vehicle that includes such a system necessitates a powerful engine and often will still be relatively