1 qty – #1 Fuel Line (OE # 7C3421, 4P9661, 1917941, 4P3921). 1 qty – #2 Fuel Line (OE # 7C3422, 4P9662, 1917942, 4P3922). 1 qty – #3 Fuel Line (OE # 7C3423, 4P9663, 1917943, 4P3923). Fit for Caterpillar models: 3406, 3406B, 3406C, 980G, 980F, D8R, D8N, 826C, D400E.