BMW 1 2 3 4 5 Series Fuel Cap RETAINING BAND TETHER CORD STRAP Z3 Z4 X1 X3 X5

So before ordering your new tether also check your internal seal for cracks. Petrol & Diesel. A common problem with the all BMW models is the small rubber cord that tethers the fuel cap in place to prevent loss during filling of the fuel tank.