Force Sensing Resistor 0.2’’ Diameter Circle is a passive component that acts as a variable resistor, with resistance decreasing in response to increasing applied force, which makes it easy to add a touch interface to your project .
The polymer thick film (PTF) device is optimized for use in human touch control of electronic devices and can sense an applied force anywhere in the active area ranging from a few dozen grams to a few kilograms (0.2 N to 20 N).
In the tests, the resistance exceeded 1 MΩ with no applied pressure and ranged from around 100 kΩ to a few hundred Ohms as finger pressure varied from light (a few dozen grams) to heavy (pressing as hard as possible). The resistance is very stable when the pressure is fixed, and the readings are very repeatable.
This resistance range is well suited to work directly with the internal pull-ups of many microcontrollers such as AVRs and PICs. 
The two male pins (called “solder tabs”) have a 0.1″ spacing, which means they are compatible with most solderless breadboards.
 
Features:
Stable and repeatable sensor readings
Breadboard compatible
Flexible, light and thin
0.2’’ active sensing area
Responsive to light and rapid taps
Compatible with microcontrollers such as AVR and PIC
Sensor Diameter: 0.3’’
Active Sensing Area Diameter: 0.2’’
Thickness: 0.01’’
Weight: 0.15g