What O-ring size is recommended for the bottom air supply ports of the MaxxMacro 70 chuck (MM-PKLPR000)?

For the bottom air-supply ports of the MaxxMacro (System 3R OEM 100% cross-compatible) 70 chuck (MM-PKLPR000), use an AS568-104 O-ring in NBR (nitrile), 70 Shore A, or an approved equivalent.

The nominal dimensions are 2.84 mm inside diameter × 2.62 mm cross-section, with an 8.08 mm outside diameter.