Air Torque
Air Torque PT400-S09-H PT400S09H, PT400 S09 H Pneumatic Valve Actuator NEW
It measures 1 inch x 2 inches x 1 inch, so it works with other small parts.
Air Torque PT400U Pneumatic Valve Actuator w/ Westlock Controls 9479NBY2B2M0600
You will find that Oxford cloth keeps its shape even when stuffed full.