A small locking device fitted to the end of a peg hook that stops items being pulled off, removed with a key.

It is the cheapest and most widely used peg hook protection, and it can be retrofitted to standard hooks.

The customer can see and handle the front item but cannot remove anything without staff.

Some patterns allow one item to be released at a time, which lets the customer serve themselves while preventing a sweep.

Keys are typically common across a store or a chain, and that is the system's principal weakness.

They are also used on shelf-edge and slat wall fittings, not only on peg hooks.

Small, high-value, easily concealed goods with a resale market - and the list is usually short and well known to the store.

Razor blades, batteries, memory cards, cosmetics, over-the-counter medicines and specialist consumables are the recurring examples.

The common factor is high value in a small package, not high value alone.

Loss data should decide the list rather than assumption, because targeted lines change and hooks left on untargeted stock suppress sales for nothing.

Protecting a whole aisle is usually the wrong answer: it slows every sale and dilutes staff attention.

Review quarterly against actual shrinkage, and be willing to remove the protection as well as add it.

Count the keys, secure them out of hours, and treat a missing key as a reason to change the lock set - because one key defeats every hook.

Stop lock keys are small enough to pocket and are frequently common across a whole chain, which makes a single stolen key valuable.

Keys left on a till overnight, or on a lanyard that goes home, are the normal failure.

Check the set against the register at each handover, and lock them away at close.

Store-specific or chain-specific coding limits the damage when one is lost, and is worth specifying at purchase.

Keep a register of how many exist and who holds them. Most stores cannot answer that question when asked.

The fully locking patterns do, because every sale needs a member of staff - which is why the self-release designs exist.

An impulse purchase that requires finding an assistant frequently does not happen.

Time-delay and ratchet hooks let the customer take one item themselves, which keeps the sale while preventing the sweep.

Where staff assistance is unavoidable, the fixture needs to be somewhere staff actually are, not at the far end of an aisle.

The comparison is between shrinkage saved and sales lost, and for low-margin lines the answer is often not to protect them at all.

Measure it if possible. Sales before and after fitting hooks on a line gives a real figure rather than an assumption.

Usually yes - stop locks fit standard peg hooks, though hook diameter and profile need checking.

Most stop locks are designed for the common peg hook wire diameters and slide on from the front.

Non-standard, heavy-duty or flat hooks may need a different pattern or a replacement hook.

Where the fixture is a shelf rather than a hook, shelf-edge and pusher-based devices do the equivalent job.

Replacing hooks entirely with integrated locking hooks is tidier and more secure but considerably more expensive across a store.

Test a sample on the actual fixtures before ordering. Peg hook profiles vary more between fixture suppliers than expected.

Hooks limit how fast stock can be removed; safers stop an individual item being opened or concealed. They protect against different behaviours.

A stop lock defeats the sweep but does not stop one item being taken and concealed by someone who works at it.

A safer case makes an individual item bulky and hard to conceal but does nothing about the number taken.

For very high value per unit, safers are usually the answer. For moderate value taken in quantity, hooks are.

Some stores use both on the worst lines, which doubles the till handling and is reserved for genuinely targeted stock.

The decision should follow the loss pattern: whether stock disappears in ones or in handfuls.

Very little mechanically - the real maintenance is the key register and checking the locks are actually fitted.

Stop locks are simple and durable, and physical failure is rare.

What happens instead is that they are removed during a restock and not replaced, leaving the line unprotected while everyone assumes otherwise.

A periodic walk of the protected fixtures checking every hook has its lock is the control that matters.

Missing locks accumulate at tills and in restocking trolleys, so a return routine is worth having.

Reconcile the number of locks against the number of protected hooks occasionally. A shortfall usually explains an unexplained rise in shrinkage on that line.