Know the names Maina, Mwangi, Irungu, Juma are kalenjin age set after cut.
128 years can be arrived at basing on the Kalenjin 8 agesets also used by the Luhyia,Kikuyu and others. They are:
Maina,
Nyongi(Mwangi,Abanyangi),
Chumo(Abachumo,Cuma)
Kipkoimet(Abakikwamet),
Korongoro(Irungu,Abakolongolo),
Kaplelach(Abananachi),
Sawe(Basawe),
Kipnyige( Bakinyige)