M2X6/D7985 is a model of lock nut manufactured by Kraftberg, a German producer of industrial locks and other hardware. It is a metric-sized slide lock nut, made of brass and featuring a zinc-plated finish. The lock nut is designed to hold fasteners in place and prevent them from loosening over time. It features an internal thread for mating with the corresponding external thread of a fastener, and can be secured in place by turning the nut to clamp down onto the fastener.