This will depend on the surface you are using it on.  The T5-J will work on almost all grating that has vertical flat bars, either with square holes or rectangular openings.  If you have I-bar or T-bar grating, you will need to use the T5-L.  If you want to use them on solid flooring, such as concrete or deck plate, you may have to replace the hardware with anchors or threaded fasteners.