Fiberglass ƙarfafa filastik abu ne mai ƙarfi mai ƙarfi, nauyi mai sauƙi, juriya ga lalatawar acid da alkali, wahalar konewa, da haɓaka mai kyau.Saboda kyawun robobin sa, ana amfani da shi don ƙirƙirar sassaken dabbobi daban-daban.Daga cikin su, doki, a matsayin tsohuwar dabba kuma kyakkyawa, shi ma yana ɗaya daga cikin jigogin da masu sassaƙa ke zabar su.