Our plastic deck sleeves are designed with a groove running from top to bottom. Fence posts with Lock-in-Deck, include a screw at the bottom which fits into the groove of the sleeve. You will insert your post into the sleeve, aligning the screw with the groove. Once fully inserted you can twist the post to misalign the screw with the groove. This locks your post in place. To unlock, twist the center of the post to align with the groove and pull the post out. This patented feature is only offered by Protect-A-Child. Learn more about our Lock-in-Deck and other added layers of protection on our SureSafe FeaturesTM page.