I have the following filters for sale: #282 250 hz #285 500 hz #288 1.8 khz $75.00 each + $3.00 Priority Mail. Vince Santis , N1VS 116 N. Main St. Winsted, CT 06098 vsantis at earthlink.net --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.537 / Virus Database: 332 - Release Date: 11/6/03