4. The bottom of the JounceShock, where the nylon cupped or domed foot threads onto the shaft. Note the yellow cap in the center. Under this cap is a Schrader valve for changing the nitrogen pressure or the oil. My J'Shocks came with 80 psi of nitro, which proved to be too stiff for the 3,500-pound Bee. Reducing the pressure to 40 psi made a huge difference. By the time you read this, Light Racing will have probably reduced the initial 80psi pressure to 40 in all its universal applications. Also note the small hole at about 4 o'clock on the shaft. This is one of two holes around the base of the shaft that contain adjustment screws for fine-tuning the compression and rebound valving.