This is the Outerwears Pull-Starter Pre-Filter (Yellow) for the HPI Baja 5B buggies.  These will fit most 23-30cc Zenoah or Zenoah cloned motors (CY) fitted in a HPI Baja 5B or most other R/C cars and scooters.  These are washable, reusable, and come complete with instructions and hardware.

Use this Outwears Pre-Filter on your HPI Baja 5B pull start to help protect your engine. The pre-filter will reduce the amount of weeds, grass, and dirt that will enter you pull start through the large openings found on the pull-start assembly. Garbage that gets into your pull start will not only make pull starting difficult, but will also reduce the amount of air that comes into your flywheel, possibly causing your engine to overheat.

Picture below is to show what product looks like installed.  The actual color of the item in this listing is what is shown above.