Musical instrument effects pedals are powered from adjacent pedals by providing electrical connectors between adjacent pedals and by providing tip-ring-sleeve jacks in the pedals and three wire connectors with tip-ring-sleeve connectors, which carry sound signals from an instrument through sequential pedals and electrical power in an opposite direction to the pedals. The half bearing having a main semi-cylindrical part, two crush reliefs, and two transition regions. The film containing the above element is rendered flowable by performing a heat treatment. The etching process is capable of transferring the main pattern feature to an underlying layer, such that the sacrificial pattern feature adjusts an etching behavior of the main pattern feature and is eliminated from the underlying layer. Various types of reference measurements of the calibration structure are made with the probe or vice versa to calibrate it. The housing member is provided with a penetrated space for receiving a light-source unit in the lighting unit therein.