This O-ring, 15.54 mm I.D. by 1.78 mm width, is used with Optima® 5x00/7100/7200/7300 DV/8300 ICP-OES series instruments. It is designed for use in the torch clamp on the vertical torch module.
This o-ring is included in the Complete O-ring Kit for Optima 4300V/5300V/7300V (N0770916).