1. Verify that all the parts are present.
2. Slide the bottom tube into the top tube. Install one of the locking knobs into the top tube and tighten. Installing the bottom tube as shown will have the O2 tank on the right side of the seat. To have the O2 tank on the left side of the seat, flip the bottom tube 180 degrees and install into the top tube.
3. Install the bottom tube into the accessory mount on the seat bracket. Install the a locking knob onto the accessory bracket and tighten.
4. Install the remaining 4 locking knobs on the O2 brackets.
5. Slide the bottom O2 bracket onto the mounting bracket to the bottom of the mounting bracket, with the O2 bracket facing the middle of the bracket. Tighten the bracket. Slide the top O2 bracket onto the mounting bracket. Set it to the height appropriate for the tank being use and tighten.