Most of our lenses and other circular components can be supplied from stock in standard mounts. This greatly simplifies the construction of optical systems by protecting components from damage in handling and providing mechanical interfaces to other components. Full details of our range of mounts and holders are given in the relevant sections – see TubeMount and Component holders. Components available ready-mounted are noted in the relevant sections, and the following types of mount are available. Type MB – basic cylindrical cell, Type ML – cell with threaded spigot to attach to another cell or other TubeMount element. Type XB – cell with flange to mount on flat surface (perpendicular to optical axis. Type HD – holder with M6 female thread in base to attach a mounting post or direct mount to a breadboard or similar surface (parallel to the axis).