Gibraltar Tension Lock Tension Rods feature interlocking flex receivers at the top that prevents the rod from backing out and detuning the drum under hard playing.
The bottom of the flex receiver fits snugly into the oval cutouts in most counterhoops, locking into a fixed position. The special shape of the upper cavity corresponds to the metal tension rod's unique "collar", and when completely inserted it will not allow the rod to rotate without a drum key.
One of the best features about this design is that the rod and the lock are one piece - that's less of a chance to lose parts.
At 2.75" long, these tension rods are designed for very deep drums with a moderate amount of distance between the lug casings and the counterhoops.