Dual farantin duba bawul kuma ake kira wafer irin malam buɗe ido duba bawul, lilo cak bawul.TNau'in bincikensa yana da kyakkyawan aikin da ba zai dawo ba, aminci da aminci, ƙaramin juriyar juriya.It an fi amfani dashi a cikin man fetur, sinadarai, abinci, samar da ruwa da magudanar ruwa, da tsarin makamashi.Akwai nau'ikan abubuwa masu yawa, irin su simintin gyare-gyare, baƙin ƙarfe, bakin karfe da sauransu.