Black's offer a great range of men's zip-off trousers. Adaptable item of menâs clothing, zip-off trousers can easily convert to 3/4 length trousers or shorts, so you can modify your outfit to suit the conditions. Packed with technical features, some great brands like Craghoppers and The North Face have zip-off trousers with multi activity convertible trousers giving great performance and are ideal for travelling or day trips.