I have 2 Inrad #761 filters that are now surplus as both the Omni VI+ and Orion have found new homes (New Orion II is now up and running!). The 761's are 9 MHz IF filters for the ORION or OMNI VI+ and are 1.8 KHz. Both are like new in their original packaging. The Inrad #750 is sold. $75 each plus $3.85 Priority Mail postage 73, Mike W9MWS