885b6512_Spatial_Join__Analysis___Datatype
[Parameter] Search Radius (Optional) [Explanation] The distance over which the analysis is performed. A distance of 0 (default) means that only features that physically touch are matched. A distance of -1 means that the analysis will search as far as it needs to find a match. It is only valid to use -1 as a distance for joins that use a nearest join option. The distance will be in a unit of measure defined by the tool. Otherwise the units associated with the output coordinate system are used. [Datatype] 
Linear unit
F e a t u r e L a y e r
F e a t u r e C l a s s
S t r i n g
B o o l e a n
F i e l d M a p p i n g s
L i n e a r u n i t
Spatial Join (Analysis)