Icarus 3000U Mode C Altitude Serializer 3230015-3 was used in my Cessna 182T connected to the encoder

Good condition was working when removed for upgrade.

The Model 3000U Altitude serializer connects to the existing Mode C encoder in the
aircraft. It converts the gray code into a decimal format and sends it to the GPS receiver
using a serial connection. It will function with Trimble, Garmin, Northstar, and UPSAT
(iLINC) GPS receivers and MFD’s. King KLN series receivers are not compatible with
the 3000U

associated with transponders