Inflating Your Fenders Correctly
Get the Correct Pressure
It is very important that you inflate your fenders to 2PSI
If you under-inflate them they will not perform correctly and may not protect your boat as they should. 
If you over-inflate them you the sides will bow out, distorting the fender, causing all the abrasion to be in one place    
and for the fender not to absorb the impact but to cause you to bounce off the pontoon, wall or another boat.
Over-inflating your fender will void the warranty.
Inflating to 2PSI will allow you to depress the walls with your thumb by about 1/2 centimeter with only light pressure.
 Correct        Incorrect
 inflation       inflation
Inflating Your Polyform US Fenders
Polyform US fenders have a unique vinyl valving system with a nylon screw that ensures an airtight seal. 
If, at first, you have trouble getting air into the fender just push a thin phillips head screwdriver (or equivalent thin piece of blunt metal) down the valve to open the little return flap at the bottom of the valve. You should then find air will go in easily. Please note the SCREW is the airtight seal not the return flap. If some air escapes before the screw is replaced don't worry!
After filling remove the pump and carefully replace the screw.
Note: You are screwing a plastic screw into plastic threads. The screw will come to a stop when the screw head is flush with the top of the valve casing. Do not force the screw past this point or damage to the valve will occur.
All our fenders come with a free inflation adaptor which can be used with handpumps or footpumps.  If using a compressor or garage airline remember 2psi only and you will probably not need to use an adaptor.