Maximum strength for maximum projects. When your project demands serious holding power, reach for the Super Mix. Whether sewing or gluing, our three ultra-strong magnetic champions tackle the toughest jobs – thick leather, layered bag construction, elaborate cosplay builds. No slipping. No shifting. No compromise. Because some projects don't take prisoners. The 3-pack is a perfect trial pack for those new to using SewTites (it also makes a lovely stocking stuffer or gift), while the 12-pack is a great value for those who know they'll use allllll the SewTites. All SewTites are made with high-quality rare earth magnets. The Super Mix contains: Ultra - 1.72” x .71"" (45 x 18 mm) with two very strong earth magnets on back + matching metal plate HD - 2.125 x .5625"" (54 x 14.5 mm) with three very strong earth magnets on back + matching metal plate Magnum - 3.98” x .59” (101 x 15 mm) each with five stronger earth magnets on back + matching metal plate