Brian Van Daalwyk

I recently got a weed eater string trimmer from a guy at work who was cleaning out his late fathers shed and I need some information about this trimmer. The tag that normally has the model number on it is ripped apart, so I only know a couple of items about it. I hope with the below information and the picture, you can help me answer the (4) below questions.

1) - What is the model number of this trimmer?
2) - What is the gas/oil mix ratio?
3) - What is the string diameter I should use?
4) - What Champion model number spark plug do I use?

Misc information about trimmer -
- Weed Eater Feather Lite
- Serial #95121N
- Engine Family - SPW018UB23RA:EM
- 18CC engine
- The tag says this trimmer complies to 1995 regulations