You are buying a CW filter:

 

This is the optional 500Hz CW filter for the FT-1000 and FT-1000D, at the 455KHz 3rd IF.  Also known as XF-E in the manual.  For improved reception on CW and RTTY.  Easy installation, just clip a diode and plug this in.  Excellent working condition.  Full proceeds go to charity - thanks!

Will be shipped within 24 hours of receipt of payment.  Check my 100% feedback rating and buy with confidence.  Thanks for looking!