All O-Rings you need,Nitril, oxygencompatible, in a small Box:

HP-Swivel, 1.42x1.78, 10x, 3/8" hose to 2. Stage 10x, 10x Hose3/8" to 1. Stage, 10x HP 9.25x1.78 7/16 UNF Highpressurehose to 1. Stage 10x, 10x 1/2" Hose to 1. Stage 10.82x1.78, 1/4" B.S.P Threads 10x2mm, 10x 12.42x1.78 for Cylinder valves, 11.00 x 2.62 1. Stage-O-Ring Apeks 10x, 10x 1. Stage-O Rings different Brands, 10y Cylindervalveseat 12.00x2.62, 5x 3/4B.S.P. Valve to Cylinder, 25.0x3.53 5x M25 Valve to Cylinder.