These button cell batteries by ASG will power most red dot scopes.
ASG 1 5V AG13 / LR44 Batteries Torch Laser
1.5V Battery, AG13/LR44, 10 pcs.
Ag13 Lr44 Alkaline Button Cell Battery Ag13 Lr44 1.5v Button Cell Battery - 100pcs - Aliexpress
AG5/393A Knoopcell batterijen (10pcs set)
AG13 ALKALINE BATTERIES 10-PACK
AG13 - LR44 Button Cell Batteries - 10 Pack — Fantasy Gifts
Spare Batteries - AG13 - LR44 Pack of 10 – Talking Products Ltd
Battery AG13 / LR44, 6-pack
AG13 ALKALINE Cell batteries LR44