The Saiga is manufactured by Ishmash in Russia. It is the original AK plant. To meet import restrictions, it is made in a 'sporter' configuration...no pistol grip, bayo lug etc. Internally it is almost identical to a traditional semiauto AK, with a couple minor tweaks. It uses proprietary magazines and has an extended trigger bar with resulting nasty trigger pull.
I 'unconverted' my x39 Saiga a few years ago and am somewhat familiar with the differences.