Pair of new 1" upper tension discs. They are compatible with many older Singer sewing machine models including the 15 (15-30, 15-90, 15-91, etc), 27, 28, 66, 99, 127, 128, 201, 221 / 222K Featherweight and the 301 / 301A. Part #2102, you will receive two discs. 1" OD and 1/4" ID.