ProtoBox Kits BusBoard Prototype Systems' assorted ProtoBox Kit Series save time in that the PCB is designed for the box, with no cutting required. In addition, the convenient 2-hole ProtoBoard pattern makes connecting parts easy while maximizing usable board area. The PCB is made from lead-free etched copper with a flux coating which allows easy soldering and preservation of solderability. Each kit contains Prototyping Board with compatible hand-held case or enclosure. The following ProtoBox Series are available, each with its own unique design, size, and configuration: 1593, 1553, and 1590.