Features:
An enjoyable "old-timer" alternative to Nitro operation
Includes instructions - 
Two (2) spare teflon discs
30cm (1') of diesel fuel line
Brand new  Current Production items
 
Head gasket is not included
For reed valve engines a heavy duty crank is recommended
 
Application:
All Cox .049 engines (Post 1956)
All Cox .051 engines

This head conversion requires a special mix of fuel consisting of kerosene, ether and castor oil. 
See here for basic details: https://coxengines.ca/public/files/FG.pdf
See here for more details: https://coxengines.ca/public/files/DFD.pdf