Defender - one of the main and one of the most popular Russian Bodyarmor. Used by FSB, sometimes police units, army and another structures. Very comfortable, affordable and nice bodyarmor. If you are just starting making your Russian Kit - that's they best choice.
Here you can find more modern Generation of Defenders - Molle Defenders. They are created for Special Force, who prefer to put pouches directly on Bodyarmor. Plus here you can find modified defenders, from SRVV and Stich and etc.
Here you can find different Defender parts, like plates, groin pads and etc.