Sensors

Ultrasonic Range Finders

SRF05 Low Cost Ultrasonic Range Finder.
SRF10 The Worlds Smallest Ultrasonic Range Finder.
SRF10 Mounting Kit
1 x Mounting Bracket
2 x Molded Rubber Grommets
2 x Self Tap Servo Screws.
SRF08 High Performance Ultrasonic Range Finder.
SRF235 "Pencil Beam" Ultrasonic Range Finder.
The SRF235 is a small sonar with an industrial air coupled transducer, giving a very narrow 15° beam width and fast cycling - up to 100Hz update rate. Working at 235KHz, the SRF235 can be used simultaneously with standard 40KHz rangers without interference.
SRF04 Original Ultrasonic Range Finder.

Thermal Array Sensors

TPA81 8x1 Thermopile array. 8 Pixel Thermal Array Sensor. It detects a candle flame at a range 2 metres (6ft) - unaffected by ambient light. Detects Human Body heat. Servo control for image construction.

Compasses

CMPS03 Magnetic Compass Resolution: 0.1 Degree; Accuracy: 3-4 degrees approximately after calibration.