The Quick Bayonet Mount (QBM) is the bayonet mount system for the range of interchangeable lenses fitted to 135 film cameras built by Rollei in Germany and Singapore from 1970 through 1990, including the Rolleiflex SL35, Rolleiflex SL2000F, and Voigtländer VSL series.

Lens brands sold with QBM included Carl Zeiss, Rolleinar, Schneider, and Voigtländer.

QBM has a flange focal distance of 44.5 mm.

The aperture ring should be set to its maximum position (smallest f/-number) before mounting on the camera.

The depth-of-field preview should not be engaged during the mounting/dismounting process.