Peugeot 245009 Clef du Vin Professional Pocket, Stainless Steel A patented metal alloy, the Clef du Vin is a calibrated instrument that reveals a wine's aging potential It works effectively on all types of wines: whites, sparkling, rose, reds and naturally sweet wines Each second the alloy disk is in contact with the wine will mimic one year's ageing: the effect is cumulative and irreversible The pocket size is easy to transport in a pocket or purse; calibrated for a 100 ml glass of wine Perfect for wine collectors, oenophiles and those who just enjoy wine.