RURBRIN (5+5 Sets) 3/8" & 1/2" Impact Wrench Retainer Rings with O-ring, Fit For Electric/Pneumatic Wrench, Including Anvil Retaining Ring Install Tool - Amazon.com
O-ring fitting | damage-free assemby | installation instructions for o-rings
O-Ring Installation Machines - CDS Manufacturing
Figure 7-10.O-ring installation.
Tips for Proper O-Ring Installation | Special Sealing Products