A simple indicator attachment to make your DTI (clock) more versatile. There are Two fingers included so you can now align the vice jaws to your milling table and get bores running true on your lathe are two examples of use. Not perfect I know but better than nothing, more for indicating than actual measurement. Similar to a starret version which unfortunately I don't own. This is much cheaper almost free and the lot can be printed in 20 minutes. No need for supports or rafts or anything just print it.