single: Unit of Measure
sell-product-in-multiple-unit-of-measure.rst sell-products-by-multiple-of-unit-per-package.rst purchase-meat-in-carton-20kg-each-keep-stock-in-cartons-per-kg-and-sell-in-carton-or-kg.rst purchase-led-lights-in-pack-of-25pcs-and-sell-single-unit-or-pack-of-25pcs.rst