ACK A30 Altitude Encoder ACK encoders are compatible with virtually all transponders in use today including MODE S. The ACK A30 mode 4 is (FAA TSO C-88A) approved to 30,000 ft. The mode 8 is now approved to 42,000 ft. with two RS232 outputs. ACK ELT's are all solid state and include a complete 4-foot harness, mounting tray, 4-foot static hose and fitting, a connector kit and installation manual. Size: 5.5" x 2.5" x 1.5". Weight: 0.5 lbs. Made in the USA. The ACK A30 Mode 8 is now approved to 42,000 feet! Features: -Approvals: FAA TSO-C88a -Range: -1000 TO 30,750 Feet -Accuracy: Typical +/- 20 Feet; Maximum +/- 50 Ft. -Size: L x W x H 6 x 2.65 x 1.7 Inches -Weight: 7.1 Oz. -Operating Voltage: 10 to 32 volts -Operating Current: 150 mA -Operating Temp: -4 to 131 Degrees F ; -20 to +55 deg. C -Compatibility 4096 Code Transponder: Compatible with virtually all transponders in use today -Mode S compatibility: Compatible with all classes of mode S Transponders -Package Size: 9 x 6 x 4 Inches -Package Weight: 1 lb.4 oz.