The MK-LS-AB vertical form fill seal machine offers in-box packaging operations, and performs automatic weighing, box opening, filling products, and package sealing. With a high degree of automation, labor costs are significantly reduced, and a multi-head weigher is used to accommodate packaging of single hardware fittings in large amounts or heavy weights, such as screws, nuts, or eccentric wheels. The filling weight is freely adjustable according to customer requirements, thus meeting customer needs for handling different materials within the packaging machine.