the turret, the gunner's station is on the right and the commander's station is on the left, each with a single hatch cover. The turret traverses through 360°. Traverse and weapon elevation is by all-electric digital control. Both the gunner and commander have a turret stop button and are able to lay and fire the weapons. The gunner has the turret control box mounted to the right of his position and both turret-crew members have an adjustable seat. The communications equipment is installed in the turret bustle. The basic production models lacks an in-built air conditioning and NBC protection system, but can be fitted if/when needed. Aiming The gunner has a twin-control handles and a day/thermal sight, with a magnification of x8 and two fields of view (high and low), with stadias for the 25mm cannon and 7.62mm coaxial machine gun. The commander has an optical relay from the gunner's sight and a single control handle. The vehicle commander has a further five day periscopes to give observation to the turret front, left side and rear; the gunner has three periscopes (1 x M17 and 2 x L794D) to give observation to the right and rear. Variants Prototypes XV1 and XV2 - During the experimental phase, two experimental vehicles were built. The first experimental vehicle, XV1, was conceptualized in August 1989 and rolled out in January 1990 while a second and third vehicles, XV2and XV3, based on a new design, was rolled out in December 1990 and March 1991. They were used to test the new running gear and power pack systems as well to firm up the IFV specifications. By January 1993, the first testbed was available; testbeds 2 and 3 were made ready in June 1993. With the acceptance of the IFV by MINDEF, the final prototype and pre-production model rolled out somewhere between July 1995 and June 1996. A total of 9 trial platforms were built in the years up to 1997. Interim Armored Vehicle - The variant was designed as an entry for the US Army's requirements for its Interim Brigade Combat Team (IBCT) concept in 2000. The original turret was replaced with a US-designed and built Recon/Optical stabilised remote weapon station armed with either a 12.7 mm M2 Browning machine gun, a 7.62mm machine gun or a 40mm automatic grenade launcher. The replacement of the original turret decreased the overall weight to 17 tonnes, light