Medical grade Polypropylene calibrated, �measuring jugs� The most durable polypropylene calibrated, measuring jugs on the market. Supplied mainly to the agricultural, science and wine industry in South Africa for the past 34 years. � These medical grade virgin polypropylene calibrated jugs can be branded with your company logo, product name or re-calibrated with your product measurements. We only use virgin raw material in our manufacturing of these jugs to secure the print results is.