This Force Sensor has a sensing area of 1.75 x 1.5″, sensing area and it will vary its resistance depending on how much pressure is being applied to the sensing area. The harder the force, the lower the resistance. When no pressure is being applied to the FSR its resistance will be larger than 1MΩ.
This Pressure Sensor can sense force anywhere in the range of 100g-10kg and can be easily integrated with Micro controllers, Arduino Boards, Raspberry Pi etc. using an Analog to Digital Converter (ADC).