The unique design of STABILOC user-friendly assembly allows the STABILOC lock to be inserted vertically into a receiver, which has been retrofitted into the manhole cover. This process orients the STABILOC lever arm parallel with a vertical wall of the manhole cover frame.

The lever arm detent is tandem spring biased against a tab on the lock body. Depressing the bolt head into the lock body extends tandem springs anchored to both the lock body and lever arm. This action releases the lever arm detent from the lock body tab, and rotates the lever arm into a near horizontal position for tightening into its receiver.

When installed, the STABILOC is flush with the manhole cover surface.

When the anchor bolt is tightened, the STABILOC receiver forces the lever arm to rotate into locked position, and a powerful clamping force is exerted upon an adjacent wall of the manhole frame. This locks the manhole cover securely in position.

The STABILOC system has been engineered to be highly effective and provide many years of reliable security. No indexing of the manhole cover is required for most installations; this feature alone saves an enormous amount of labor time.