Nondetachable types.

K.L.G. 348   Stands great heat but very little oil. Should not be necessary except for Brooklands. 
 K.L.G. 341  This Plug is recommended but only for sustained " full out " use. Will stand more oil than 348 but oils easily unless engine is well warmed up. 
 K.L.G. 464  Stands less heat but more oil than 311. Recommended for Road Races such as the TT  
 K.L.G. 356  Stands less heat but more oil than 464.

Detachable Types.

 K.L.G. 396  Highest heat resistance of the detachable types but less than any of theabove. Recommended for short road circuits or grass track events.
 K.L.G. 583  Recommended for touring with KTT engine, also for warming up engine previous to fitting any of the above.