Chamber Flags are used to visually show that a Weapon is SAFE from a glance. Also known as Open Bolt Indicator (OBI) or Empty Chamber Indicator (ECI), the brightly colored flag obstructs the firing chamber and alerts the range officer and other shooters that the fire arm chamber is empty!
All Chamber Flags – Plug'r USA
Kleen-Bore Chamber Safety Flags 9mm to 45 Cal Pistol Nylon Orange 2PK
Pridefend 10 Pack Chamber Safety Flag for Rifle
Empty Chamber Indicator - Flagazine by DeWZ
UTG Universal Firearm Chamber Safety Flag, Orange
ECI--YELLOW Empty Chamber Safe Chamber Flags Rifle Pistol Range Safety ORANGE
Chamber Safety Flag
10 Pack Open Chamber Indicator Safety Flags (Safety
Empty Chamber Indicator « Daily Bulletin
Empty Chamber Safe Chamber Flags Rim-Fire Rifle Pistol Range
TAC Chamber Flags — TAC
Chamber Safety Flag for Rifle Handgun Shotgun, 6