The Designer Systems X4 is a rugged terrain rover (kit) with 4 wheel drive and knobbly tyres capable of traversing steep inclines and rough terrain with ease. The kit includes all mechanical parts, a 7.2V NiMH rechargeable battery, mains charger and DS-X4C controller board, fitted with dual infrared collision sensors, to produce a fully working autonomous rover. Fixings are also provided to support the Savage Innovations Inc. OOPic-R controller board and many other add-on modules. A base expansion kit and solar re-charging module are also available.