From
www.echostaruser.org....Under Systems
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Accessories
If you have trouble controlling your VCR from your 4700 or Dishplayer, you can connect an IR mouse extender to the accessory port on your receiver.
Order a "Blast IR extender, (mouse tail)", Echostar part # 123479181. Dish's dealers don't usually stock this part, but you can order it directly from Echostar. Call DISH's parts dept. (which is also the Return Authorizations dept.) at 888-220-3474.
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The mouse tail has a specific connector, i. e. other's will not work. All receiver's since the 4700 support this.