Missing Homework - ExcelMark Self-Inking Two-Color Rubber Teacher Stamp - Perfect for Grading Homework - Red and Blue Ink Features a dual-color, Red and Blue ink pad that doubles the number of impressions and the useful life of the pad Thousands of impressions before re-inking is necessary Red stamp mount with a clear base to easily align impressions Impression Area: 1/2" x 1/1/2"