This grenade is identical to the M50P2 and M52P2, but issued with a modernized fuze, the PU M-69. The grenade body was marked as a normal M50P2 or M52P2 but the fuze was marked on the top of it's protective cap as M-69.
Factory RZK(REMONTNI ZAVOD KRAGUJEVAC) was replacing old M-50 fuzes on M-50 and M-52 grenades with these new PU M-69. These modernized grenades with the new fuze were called M50P2 and M52P2. M50 grenades were modernized with the PU M-69 fuze first, the M52 grenades were altered after that.
The project of modernizing M-52 grenades with the new fuze started in RZK factory in 1969, so they called that modernized grenade M-69. M50P2 and M52P2 represent the same grenade.