These O-rings can be inserted on your 1911 grip screws and help them from shooting lose by filling voids and applying tension from the rubber under load.  These units will likely be single use - they wear each time the screw is torque down so that is why we sell them 8 at a time and not 4.

This size will fit just right under the head of 1911 grip screws and are made from Buna rubber to withstand oil.  I selected O-rings that provide a balance of flexibility and firmness to allow for firmly seating each screw.

The price is for 8 rings.  So you have the four you need - one for each screw and then four more spares.