Wort Thief and Test Jar Combo, Graduated Cylinder for Hydrometer Sampling (BSG)Draw, test, and replace in a single tool. This combination wort thief and graduated test jar lets you pull a hydrometer sample directly from the fermenter and read specific gravity right in the same vessel. No separate cylinder, no pouring back and forth, no extra glassware to sanitize. The molded graduations along the side give clean SG readings from 1. 000 through the high end of typical OG ranges. Brewer's Tip: Always sanitize the thief immediately