A thumb break or retaining strap is a safety device installed on many holsters and sheaths to prevent a weapon from being unintentionally drawn.
A holster with a retaining strap.
A handgun holster is a device used to hold or restrict the undesired movement of a handgun, most commonly in a location where it can be easily withdrawn for immediate use. Holsters are often attached
An H&K P7 pistol in a holster
16th-century pistol holster from Tbilisi, Georgia
A Taurus Millennium PT145 in a horsehide pocket holster
19th – early 20th century single-loop holster