Tachometer. Fits: Oliver 2655 (D504A-6),White A4T (D504A-6), 2-85*, 2-105* (s/n 255616 and up), 2-150*, G1000 (D504A-6), G1050, G900, M670 Gas (s/n 29901892 and up) & M670 Diesel (s/n 30000820 and up. * Will need to replace cable. For a 79" cable 30V3186466, for a 95" cable 30V3493873.