71ml St/Steel Thimble Measure. Thimble measures, or Transfer measures as they are officially called by law are CE marked to comply with the weights and measures act. In short, serving a “shot” of the prescribed spirits (Whiskey, Gin, Vodka, Rum) should be used in conjunction with a thimble measure (or other Government stamped device). The UK law states that this should be served in either 25ml or 35ml or a double there of. Wine Measures exist as 125ml (small) 175ml (medium) and 250ml (large).