CR2032 Battery. Commonly used in optics like red dots and scopes with illuminated reticles
Aimpoint Acro P-2 Available in New Colors - Optics Trade Blog
Baltrade.eu - B2B shop - Varta CR2032 Lithium battery
1-4x Variable Scope (LPVO) - Novritsch
This is my pp : r/airsoft
Batteries - Airguns Europe
Holy Warrior HWO Airsoft RMR HRS Style Red Dot Sight ( Black )
SIG SAUER Air Red Dot Reflex Sight Accurate Waterproof Shockproof 3 MOA Dot 1x23mm Airgun & Airsoft Sight for M17/M18 ProForce and M17 Pellet Airguns : Sports & Outdoors
1x25 Miniature Rifle Reflex Sight - Black [BD]