A piston for use in forming a gas spring assembly includes a longitudinally extending axis, a first end wall extending approximately transverse to the axis, and an outer side wall extending longitudinally from adjacent the first end wall. A related intervertebral disc access system and pedicle screw compatible with the systems is also illustrated. The carrier is selected such that it remains mobile within the wood and provides for migration of the preservative within the treated wood. The VCO is modified to have an additional control port to adjust the duty cycle. The interface includes a bidirectional data link that can be operated in a half-duplex mode for transmission of digital payload data to be transmitted from the baseband component to the radio-frequency component and for transmission of received digital payload data from the radio-frequency component to the baseband component. The case includes a mechanism for causing a stream of contact lens solution to flow from the reservoir to an exterior of the case and another mechanism for causing the contact lens solution to flow from the reservoir into the compartments.