tender for gauge cum level (bg) along with spirit level (rdso spec.no.tm.58 dt11.06.2001) hsn code : 7608. (i) b.g. made from high tensile extruded aluminium alloytubing. the instrument mesures with precision gauge, cross-levels and superelevation by the use of separate spirit level. the gauge sets automatically at 90deg. to the rail, it is precise, rugged and convenient to use, generally andfunctionally to rdso latest drg. no. tm/0108 specification no. tm-58 but superiorapproved by rdso and railway board with spirit level model sl-2 as per rdso latestdrg. no. tm-2004, specification no. tm-52 without box. ( one set consists of 1 no. trackgauge lg-2 (l) and 1 no. spirit level sl-2.