The NOT gate is mounted on a durable, rugged plastic carrier and supplied with a lead fitted with 1x 4mm and 1x 2mm stackable plugs. Printed with the corresponding circuit symbol, making the component value and type to be easily identifiable. Each carrier is fitted with rust proof custom made spring clips, which are riveted on, ensuring a good connection to the metal pillars on the baseboard. The NOT gate is mounted on the underneath of the carrier and is securely soldered on, making repairs simple to carry out. The benefits of the locktronics system is that a working circuit can be created by directly following the corresponding circuit diagram.