When you select datum planes or planar surfaces as references for the creation of datum planes, and when the default constraint is Offset, a handle is displayed that you can use to manually drag the datum plane to the required offset distance.

You can also snap the offset handles to the following locations:

These locations or references to which the handles are snapped have the constraint type Through, while the constraint of the datum planes or the datum reference is set to Parallel.

You can also unsnap handles that are already snapped to these locations so that references with the Through constraint, such as a vertex, datum point, straight edge, curve, or datum axis, are removed, while the location of the datum plane or planar surface is maintained. To unsnap a handle, you must hold down the SHIFT key and move the handle with the mouse located close to the handle.

The snapped handle shows when the Placement collector in the Datum Plane dialog box displays one of the following selections:

The offset handle is automatically locked when you add a relation to drive the Offset dimension.