Maun safety rules metricimperial 300mm maun 1773 012 this 300mm safety rule from maun is a handy tool with a unique m profile designed to keep fingers well away from any knife edge when used for cutting or scoring card etc manufactured to a high standard with stainless steel to give a long corrosion free life and equipped with both metric and imperial scales the rule is ideal for both hobby and craft work in the educational field maun 1773 012 safety rule 12in 300mm metricimperial