This GP2Y0A02YK0F is a Analog output, 20 to 150 cm distance measuring sensor unit, composed of an integrated combination of PSD (position sensitive detector) , IRED (infrared emittingdiode) and signal processing circuit. 

This GP2Y0A21YK0F is a Analog output, 10 to 80 cm distance measuring sensor unit, composed of an integrated combination of PSD (position sensitive detector) , IRED (infrared emittingdiode) and signal processing circuit. 

This GP2Y0A710K0F is a Analog output, 100 to 550 cm distance measuring sensor unit, composed of an integrated combination of PSD (position sensitive detector) , IRED (infrared emittingdiode) and signal processing circuit.