Features:
5x3 propeller
6x3 propeller
Bulb fuel pump
Two (2) wrenches 
Battery box with clip
Engine operating instructions
Brand new Current Production items

The fit between the bulb and the cap are a deliberate tight fit, and heating the top of the bulb by using a heat gun or hair dryer, will facilitate assembly.

Application:
All Cox .049 engines
All Cox .051 engines