Replacement Caps for Stan-pac & Libbey Milk Bottles- All Sizes (12, 48 MM) BPA-free Plastic Snap Cap Lids for Stan-Pac, Libbey, & The Dairy Shoppe Milk Bottles. These lids are snap on only and do not fit threaded tops! 38MM Lids fit bottles that measure approx 1-1/2" dia at the top 48MM Lids fit bottles that measure approx 1-3/4" dia at the top- these are the most common 56MM lids fit most old bottles and decorative bottles with a large top(currently made by Stan-Pac) Please note that these caps fit ONLY bottles made by Stan-Pac, Libbey, or the Dairy Shoppe, if you wish to try them on something else, please don't bother writing a poor review or charging Amazon for the return