Name the unit used to measure mass quantity that starts with letter w
SELECT DISTINCT ?sbj ?sbj_label WHERE { ?sbj wdt:P31 wd:Q3647172 . ?sbj wdt:P111 wd:Q11423 . ?sbj rdfs:label ?sbj_label . FILTER(STRSTARTS(lcase(?sbj_label), 'w')) . FILTER (lang(?sbj_label) = 'en') } LIMIT 25 
unit of mass: Q3647172 mass: Q11423