The .50in range drum (6610) has ballistic optimisation for the current range of in-service .50in. ammunition.

The range drum is graduated from 500m to 2200m in 100m increments. It features a Gaseous Tritium Light Source (GTLS) for illumination of the range scale under conditions of low light level.

The range drum is fitted with a 32 mm male dovetail allowing attachment to the female dovetail on the weapon rear sight bracket or to the female dovetail of the .50in MG soft-mount.

The rail for attachment of the optical sight is the Mil Std 1913 Picatinny type to suit the various natures of sighting system.

There is a high degree of commonality between the various models and a full range of sub-assemblies and component parts are available where required to carry out a repair.