Redshift Constraints are made using one of six Range Types (Unconstrained, Available, Unavailable, Larger Than, Less Than, Between, and Not Between). Unconstrained means no selection on redshift will be made. Available returns only objects that have redshifts. Unavailable returns only objects without redshifts. Larger Than returns objects with redshift greater than the value entered in the box. Less Than returns objects with redshift less than the value entered in the box. Between returns objects with redshift between the Minimum and Maximum values entered in the respective boxes. Not Between excludes objects with redshift between Minimum and Maximum. Note that the Redshift Constraint is in all cases applied to the NED preferred redshift value, not to all available redshifts for each object. Redshift units of z or velocity may be specified.