The SM 8191 is a high-specification 24V voltage regulator designed for the Tata Signa range of heavy commercial vehicles. Featuring a 2-Pin L-Type configuration and cross-referenced with Ref No: 026223103 (Lucas-TVS), this unit is built to manage the complex electrical demands of modern Signa trucks, including the advanced SCR/AdBlue systems and digital instrument clusters found in BS4 and BS6 models.