| 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. | |
| 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. |