This is a Ultra-Low Profile self retracting pancake air cylinder lifter / pusher.      
The all plastic construction is moisture and corrosion resistant.      
Mounted height is .430" with an outside diameter of 2.10".      
Lifting stroke with limiter is .400"      
Inlet self sealing hose nipple is for 1/4" OD plastic hose.      
Lifter has a 200 lb. lifting force at 50 psi air pressure      
Unit snap mounts into a  1.210" hole with a .100 snap lip.      
No mounting hardware is required for easy replacement      
Multiple units can be strung together for added force.      
This lifter is used - in like New condition - with 90 day Warranty.      
Price $6.00 each (Single inlet lifter 29 available)      
Price $6.00 each (Dual inlet lifter 6 available)      
Also available to string multiple lifters:
"T" Nipple      - $0.50 each ( 6 available)
Sraight Nipple  - $0.50 each (39 available)
"Y" Nipple      - $0.50 each (28 available)
NPT 1/8" Nipple - $0.50 each ( 1 available)