eSynic 10-Pack Window Locks with Cable Restrictor for UPVC Windows (Child Safety)

The essentials

If you’re trying to reduce the risk of children opening windows too far, an in-window cable restrictor is one of those practical fixes that’s easy to understand even before you install it. This eSynic 10-pack is built around the idea of limiting how far a window can open, while still letting you remove the restraint when you need the window fully open.

The pack is aimed at everyday home use: family households, shared offices, or any room where you’d rather not rely purely on “keep an eye on things”. It’s not a substitute for supervision, but it can add a layer of control that’s there even when you’re busy.

What it does (and how it works)

On paper, the mechanism is straightforward. The window lock uses a wire cable that keeps the window’s opening distance restricted. When you don’t need ventilation to be unrestricted, the cable stays in place and effectively stops the window from opening fully.

When you do need the window to open wider, you use a key to remove the cable from one end—then the window can open completely. That “restricted most of the time, unlock when needed” approach is the main reason these locks appeal to families.

A small, realistic note: this kind of system is only as good as the installation and where it’s fitted. If the cable isn’t positioned correctly for the way your window opens, the restriction may not feel as consistent.

Key features that matter for purchase decisions

This eSynic set is supplied as 10 window locks, and the bundle includes keys and screws for installation. You get: - A set count of window restraints - Release keys for unlocking when you need full access - Self-perforating screws for an easier installation process

Materials-wise, the lock body is described as ABS, with stainless steel included in the construction. That combination is typically chosen for parts that need to handle regular use without turning into flimsy hardware.

It also comes in a white finish, which should blend in with many UPVC window frames and neutral interiors.

At a glance: fit and suitability

The manufacturer positioning focuses on window safety for children, specifically around UPVC windows, and it also states compatibility with other common window materials such as wood and aluminium.

It’s described as fitting most window types in general terms, but there’s a practical limitation you should keep in mind: without seeing your exact window configuration (opening style, handle placement, and how the sash moves), “fits most” can only be treated as a starting point. Worth checking before buying if your window layout is unusual.

Installation experience and everyday use

The installation approach is pitched as straightforward: the locks come with self-perforating screws, so there’s “less fuss” than if you needed extra drilling steps. The idea is that you can get it working quickly.

In day-to-day terms, once the cable is secured, you’re relying on a physical limit rather than memory or routine. For example, imagine a kitchen window near where kids sometimes play: with the restraint engaged, the window can still be used for light ventilation, but it won’t swing open to its full width.

Where it shines—and where it may not

Where this eSynic pack makes a lot of sense is if you’re setting up safety across multiple windows in one go and you want a consistent restriction method. The “10-pack” format is especially useful when you need the same solution around a home office, a living area, or bedrooms.

However, it may not be the best choice if you want a quick, tool-free “open fully whenever” system. Because the cable is keyed for full release, it’s more of a controlled-safety setup than a totally flexible latch.

FAQs

Is it designed for UPVC windows?

It’s described as specifically designed with UPVC window safety in mind.

Can it be used on other window materials?

The information provided says it’s suitable for several materials, including wood, aluminium and PVC.

Does the set include screws and keys?

Yes. The pack is stated to include window restraints, release keys, and screws to help installation.

How does full window opening work?

You use the key to remove the cable from one end, which allows the window to open completely when needed.

Is it a permanent restriction?

It’s intended as a controllable restriction: you keep the cable in place for limited opening, then release it with the key when you want full access.

Should you buy it?

A solid pick if you’re looking to add child window safety by limiting opening distance across several windows, and you prefer a keyed release when you want the window fully open. It also helps if you want a bundle that includes the key parts and screws so you’re not hunting for compatibility bits separately.

It might not suit you if your windows have an atypical opening setup or if you need unrestricted opening frequently without using a key. In that case, it’s better to pause and confirm the restraint positioning will work with your specific window movement before committing.