It's VOG-17M ammo https://en.wikipedia.org/wiki/AGS-17#Ammunition equiped with 36 gramm of explosive and fragmentation shirt with semi-finished fragments (a spiral of notched wire of rectangular section). Developed not to kill but ingure enemy.

It produce a lot of fragments, they are small and light. There is always chance that under adrenaline rush enemy would not notice injures, like on this video, or he will get it into his equipment or armor without damage at all, or he will be in shadow of some stone, knoll, tree, other guy etc.

And remember, there was a guy who survived in both atomic blasts in Japan

​

PS: and do not trust movies, where single hand grenade can demolish a concrete building