Fuel-Cap Retaining Tether

Three-part retaining tether for the fuel cap, explicitly shown by the creator on an R171 and described as fitting many Mercedes fuel caps. The design comprises a cap ring, flexible cord, and eyelet. The source used ASA for the ring and hard Shore D56 TPU for the cord and eyelet, while noting that approximately Shore A95 TPU may also work. Install all three parts, verify the ring does not interfere with cap sealing or locking, keep the tether clear of the filler neck and hinge, and replace it if fuel exposure, heat, or repeated flexing causes cracks or loss of retention. No other generation is linked because the creator does not identify one and no exact child-component number was established.