Abstract: A telecommunications switch chassis includes a housing which is divided into front and rear compartments by a transverse printed circuit board or mid-plane. Notches are provided in the upper edges of the mid-plane which are adapted to receive tabs projecting from the ends of a pair of card guides so that the card guides are supported on edge in proper laterally spaced relation within the front compartment. The card guides are formed with columns of slots whose edges are deformed to form slides interleaved with the slots so that the card guides can support a stack of printed circuit cards in vertical spaced relation within the front compartment, the spaces between the cards being aligned with the slots in the card guides.