The HRUSB-MaxSonar-EZ1 is a great choice for use where sensitivity is needed along with side object rejection. The HRUSB-MaxSonar-EZ1 is a good, low-cost starting place for a customer not sure of which HRUSB-MaxSonar-EZ sensor to use.
The MaxBotix high resolution MB1403 HRUSB-MaxSonar-EZ0 has a wide and sensitive beam, making it an excellent choice for use where high sensitivity or people detection is desired.
The MaxBotix high resolution MB1423 HRUSB-MaxSonar-EZ2 is a good compromise between sensitivity and side object rejection.
Waterproof ultrasonic distance sensor. This sensor can be used for collision detection in your project.
The GPS 18x is an OEM, high-sensitivity GPS sensor for use in automotive, fleet vehicle, and electronics applications that require a small, highly accurate GPS receiver.