This is the Futaba SBS-02A Altitude Sensor.

FEATURES

Detects the altitude of RC aircraft and rate of climb/descent from atmospheric pressure with vario meter
One year limited warranty

INCLUDES

Futaba SBS-02A Altitude Sensor with Instructions

REQUIREMENTS

Mounting in aircraft and connecting to the S.BUS2 port of Futaba
telemetry enabled receiver

SPECIFICATIONS

Range: 500 - 1100hPA or 162.4-16,000 ft (-700 to +5500 meters)
Weight: 0.095 oz (2.7 g)