A prototype of the locked pack, which contains the contents required to complete a central venous catheter insertion: suture, suture holder, and antimicrobial dressing. The locked pack is in the closed position and appears as it would when introduced onto the sterile field of the central line trolley. (A) The magnet in the lid and metal plate in the base, which holds the pack closed in the locked position. (B) The entry and exit channels for the guidewire. (C) The guidewire channel, through which the guidewire is inserted. (D) The hinge of the lid of the locked pack. Prototype courtesy of Venner Medical Technologies, Singapore.