I should also mention that it appears that Kobalt M is a modernized Yantar.
More correctly: Kobalt-M is a modernized Yantar-4K2 (Kobalt). Yantar is a whole family of spacecrafts. Flown versions are:
* Yantar-1KFT / Kometa: Area survey with Vostok/Zenit type reentry capsule
* Yantar-2K / Feniks: Hi-Res film return with one large and two small capsules
* Yantar-4K1 / Oktan: Improved Feniks
* Yantar-4K2 / Kobalt: Improved Oktan
* Yantar-4K2M / Kobalt-M: Improved Kobalt
* Yantar-4KS1 / Terilen: Electro-optical
* Yantar-4KS1M / Neman: Improved Terilen
There are more Yantar based satellites (civilian eo satellites Resurs-DK, Resurs-P; Lotos-S ELINT sat), for which no Yantar designation is known. There might be even more (possibly Orlets spy sats).