An optical member unit includes a light transmitting member guiding light emitted by a light source to an imaging optics system by folding the light. The downhole tool is deployed via a drill string into a wellbore penetrating a subterranean formation. The resulting compounds and compositions comprising them are useful in methods of medical treatment and diagnosis, etc. The pressure at a pressure monitoring point in a refrigerant circuit is applied to the pressure sensing chamber. The unit provides various administrative capabilities, including user account management, audit trails, transaction reports, centralized management and report capabilities, and detection of fraudulent calling. As the capsule opens, a restraint decouples from the locking mechanism and permits the resilient member to expand.