The thermoplastic molding composition comprises, based on the thermoplastic molding composition,a) as component A, at least one polyamide or copolyamide, or one polymer blend comprising polyamide,b) as component B, from 3 to 20% by weight of carbon black or graphite, or a mixture thereof,c) as component C, from 0. A cleansing chamber in the pedicure spa accepts the basin for a self-cleaning procedure. After the endoscopic instrument is properly positioned the present invention may use rapid exchange technology, soft locks, and mechanical locks to maintain the position of the endoscopic instrument.