The ignition wires can fail, the outer wire casing often cracks with age and it's also quite common for the rubber to tear at the connector, making it very difficult to get a good enough grip to remove the plug wire during routine servicing.
This is a plug wire that's made in Germany by the original supplier to BMW: BERU and it is in every way equivalent to the original BMW part in every way. The wire is complete, ready to install. Sold each, left and right are the same.
Fits single spark ignitions.
Equivalent to BMW Part Number 12 12 1 342 641 (12121342641)