First result in a Google search on "4BTV Antenna" is the web site of the manufacturer (New-Tronics) where you'll find that there's a 30-Meter Trap Kit for the 4BTV.
Part Number: 30-MKT
Price: $47.93 (Plus shipping, I presume)
See Price Sheet:http://www.new-tronics.com/main/catalogs/AmateurPriceSheet2007.pdf
TOLL FREE SALES by phone at: 877-994-9499
Further contact info at:http://www.new-tronics.com/main/html/sales.html
Mel - KS2G