NGK spark plug B7HS (Solo order number 23 00 500).
Replaces the discontinued Bosch W5AC and Champion L82C.
Spark plug cap size 20.8mm.

Technical information from Solo:
Previously in all engines and variants of the series 2350 and 2625 spark plugs from the manufacturer Bosch type W5AC were installed.
Bosch has stopped the production of these spark plugs. In the future, spark plugs from NGK type B7HS will be installed.

We recommend that a torque wrench is used at all times when tightening the spark plug (according to the torque specified by the engine manufacturer).
We supply various torque wrenches at attractive prices!