After trading several Omni series toward a Orion ,,I have several filters for sale.... 1 #282...250 hz for the 6 mg.....$65.00 shipped 1 #288...1.8 for the 6 mg.......$55.00 shipped 1 #217...500 hz for the 9 mg....$75.00 shipped ALSO...1 voice synthesizer..# 257......$55.00 shipped...many tnx and 73 all.....Mark