These 3d printed knobs are specially designed to quickly attach TrackTubes to the BORA Centipede work stand.  The knobs have a 1/4" T-bolt that catches the bottom T-track of the TrackTubes for a secure attachment.  The knob kit includes 4 knobs, 2 dogs, and 6 T-bolts sized to fit the bottom track of the TrackTubes.  The knobs can also be used with other T-slot extrusions, however, properly sized hex or t-bolts must be provided by the user.  Please watch the product video for installation demonstration.  FREE Shipping on all products.