NGK B10EG 'long reach' RACING spark plug for all tuned or kitted scooters.

The grade listings and applications for NGK spark plugs are as follows : 
B7** -  town and city use / for a standard engine 
B8** -  local and distance use / for a standard or midly tuned engine 
B9** -  competition or distance travelling use / for a tuned engine 
B10** - competition or full race use / for a high tuned engine / sidecar use 

Spark plugs with a 'BR' denomination have a built-in resistance and are designed for use with delicate electronic equipment (such as SIP rev counter / speedo units). 

Spark plugs with a 'ES' denomination have a built-in resistance and are designed for use with delicate electronic equipment (such as SIP rev counter-speedo units). 

Spark plugs with a 'HS' denomination are SHORT REACH versions (utilised for early pre-Series 1 Lambretta models manufactured between 1947-'57). Lambretta models that use a SHORT REACH spark plug are: A + B + C / LC + D / LD + E / F + Lambrettino 48.

Spark plugs with a 'ES' (standard) or 'EG' (Racing) denomination are LONG REACH reach versions (utilised for all Lambretta models with 10 inch wheels) manufactured after 1957. Lambretta models that use a LONG REACH spark plug are: S1 + S2 + S3 + GP / DL + J (all versions) + Lui Vega Cometa (all versions) + Serveta.

Spark plugs with a 'ECM' denomination are special LONG REACH reach versions ideal for tuned Lambrettas that have a (non-standard) centally positioned spark plug position (such as Casa Performance SSR250 and SSR265 Scuderia engines). These plugs have a short ceramic section, that aids frame & exhaust clearance issues that might occur with a centrally mounted sprk plug.