Woodhaven 4424 Ultra Track The Ultra Track has 8 T-slots, one each on top & bottom and 3 on each face located 3/4" & 1-1/2" from the edge. These tracks are the most versatile jig building accessories you can use in your shop. Note: T-bolts do not fit in this track. Provides an unlimited variety of quick and easy mounting and adjustment options for stops, hold-downs, etc.T-slot captures the hex head of a standard 1/4" bolt or our oval nuts. 24 long x 3" height x 3/4" width Lifetime guarantee against defects in material or workmanship. Made in the USA!