This is a force sensitive resistor with a round, 0.5" diameter, sensing area.
This very long force sensitive resistor - over 2 feet - has a sensing area of 0.25x24".
This is a small force sensitive resistor. It has a 0.16" (4 mm) diameter active sensing area.
This is a force sensitive resistor with a square, 1.75x1.5", sensing area.
