$57.99 1/2 Inch Drive Pistol Impact Wrench Friction Ring Retainer | Universal Tool | UT
Proto Impact Socket Retaining Ring, 2-1/4 ID 2-1/4 Groove Diameter JRR07536 - Walmart.com 
Astro clips 1/2 Socket Retaining clip & O-ring for impact wrenches, 5 Sets #12 | eBay
