RE: http://tech.military.com/equipment/view/89044/at4-viper.html?eq_id=89044

Doesn't the Viper have a salt water vapor expelled at the back rather than a large dangerous backblast like many other rocket launchers? That really eliminates the threat of injuring nearby friendlies. It can be shot from confined spaces without killing you and cool things like that. That would help keep you behind cover and unexposed to enemy fire and stuff. I think that should be included in the description.

regarding the pictures, number 2 is the US Army Viper, a 70mm anti tank system developed to replace the M-72 by MICOM and never adopted for service use. The AT-4 is an 84mm system which won the competition in which Viper was a candidate.

Regarding the first comment, the AT-4 CS (for Confined Spaces) uses a saline water solution as a countermass (a-la-Davis Gun) to facilitate reduced back-blast enabling use from rooms and other confined spaces with limited vent area. AT-4 was at one time produced by ATK; I'm not sure who has the current contract.