The IRYS device lets you control Icom AH-4 compatible tuners from your Yaesu radio natively. This means the radio controls the tuner, indicates the tuning state on the screen, and does not require use of the Key jack to do this. Benefits: - Use your native "TUNE" button on the radio, see tuner status on the screen- Remote-mount a tuner- Access the much wider range of available tuners for Icom radios with your Yaesu- Retain the ability to use your remote keypad *and* an external tuner! I designed this so that people at field day with Yaesu radios can use their voice keyer keypad *and* an external tuner at the same time. It also brings the extra benefit of being able to swap antennas and tuners with Icom users! This has been tested with the following radios: Yaesu FT-710Yaesu FT-991AYaesu FTDX-101MP It should work with any Yaesu radio that supports the FC-40 tuner, but the above have been tested. It should also work with any tuner that implements the AH-4 tuner protocol, but the following have been tested: Icom AH-4LDG Z-100A (and friends) The device has an 8-pin Mini-DIN plug that interfaces with your Yaesu radio's TUNER/LIN jack, and provides 4-pin Molex connector for connection to an Icom-compatible tuner. If you have a radio or tuner not on the above list and it ends up not working for you, you're welcome to send it back for a refund. If it does work with other hardware, please let me know! If you have any questions, please contact me ahead of time and I'll be glad to provide more detail, instructions, etc. Yaesu Icom AH4 AH-4 AH-3 FC-40 FC-50