This is supposed to be a stop for cutting crown moldings using the LS1013 and LS1214 saw.
The stops are handed and mount to the moving portion of the table. If you change from right to left angle cut the stops must be readjusted. If more or less than exactly 45 degrees the work must be removed and the stops must be readjusted.

These make work fine for saws that have small movable tables and the stops mount the stationery part of the table, but it worthless for the LS1013.