The Interlink Force Sensing Resistor has an active sensing area of 0.5” (12.7mm) to sense applied force.
Force Sensing Resistors (FSRs) are very thin, robust, polymer thick film (PTF) devices that decrease in resistance when increased pressure is applied to the surface of the sensor. FSRs are not a load cell or strain gauge devices though they have many similar properties.
They are more appropriate for qualitative rather than precision measurements.
This medium-sized Interlink FSR is 0.5" in diameter and measures up to 20 N.