ARC CA-550 Computer Amplifier. Condition is "Used". Removed from Cessna 210N. Worked at time of removal. Pricing to sell. If it does not work, I will give you a refund of the item cost. Refundable within 30 days. Buyer pays shipping. Shipment to US only. I try to ship same day of purchase, but I do travel quite a bit so I will ship within 3 days latest.