If you’ve got the MagSlider™ Lid, but need the magical magnet piece, you’ve come to the right place. After all, the most important part of the MagSlider Lid is, well, the magnet slider. ­­Fits all three sizes of the MagSlider Lid for Rambler® 10 oz Wine Tumbler, 20 oz, and 30 oz Tumblers.