Captain O-Ring - (6 Pack) 909 Probe O-Ring Replacement for Sumatra, Shin Sung, Sam Yang, Eun Jim Air Rifle Includes Six (6) 909 Replacement O-Rings Compatible with Sam Yang (current), Eun Jim (current), Sumatra (pre 2005), and Shin Sung (pre 2005) probes with fat o-rings 0.315" Outside Diameter, 0.112" Insider Diameter, 0.103" Thick Manufactured and Warrantied by Captain O-Ring LLC