Vintage Arctic Cat Snowmobile Used Right Tunnel Wear Plate.  Part # 0116-640.  The plate has rust and pitting as shown in the pictures.  

Fits the following models:

1977 EL TIGRE 4000 - TUNNEL, GAS TANK AND SEAT
1977 EL TIGRE 5000 - TUNNEL, GAS TANK AND SEAT
1976 EL TIGRE 440 - TUNNEL, GAS TANK AND SEAT
1976 EL TIGRE 500 - TUNNEL, GAS TANK AND SEAT
1975 EL TIGRE 340 - FUEL TANK, SEAT AND TUNNEL
1975 EL TIGRE 440 - FUEL TANK, SEAT AND TUNNEL