Not a tie-off
cleat as one would use with rope, but a device to affix electrical
wire or cable to a surface. From
Cooper Industries CTCC-10.pdf :
Cooper B-
Line Cable Cleats are designed to support and retain your cables within your cable
tray system in everyday conditions.
In-situ2.JPG
http://www.engineerlive.com/media/images/In-situ2.JPG
Sometimes called a
cable clip (again, not to be confused with the
wire rope clip.