The permanent lock is the time-proven conventional lock, which is so strong that under normal circumstances, the part will fail with the strap breaking, not slippage within the lock.
The releasable lock has been engineered so that the lock can be ratcheted and released many times and will continue to reliably lock. The releasable lock is wedge-shaped so that you can release it with your thumb even without using a fingernail. The other outstanding difference in this design is that it is the opposite of a conventional cable tie. The teeth are on the outside of the bundle diameter. In addition to the smooth strap surface being on the inside of the bundle, this reversal puts the releasable action of the lock outside of the bundle diameter, for much easier access to release.
With other releasable designs, you really need access behind the cable tie head (inside the bundle diameter) to get your finger in a position where you can easily release the tie. That is difficult or can be impossible when the part is fastened onto a bundle. This new design puts the release tab up and away from the bundle, for easy access every time.
Although this part is a natural for consumers at the retail level, there are many commercial applications for it as well.
