DS259 Double Hung Window Restrictor

Application & Project Fit

The DS259 is designed specifically for residential double hung windows with a channel size under 19mm wide — a specific enough constraint that it’s worth confirming against the window before ordering. It’s ideal for windows manufactured before 1985 and for established dwellings that require window restriction retrofitted to existing frames, rather than specified at the point of manufacture.

How It Works

The DS259 restricts both the top and bottom sashes from moving beyond a distance pre-determined by the installer, with a built-in anti-lift block. The body is key-operated and fully removable — turn the key, lift the body clear for cleaning or maintenance, then refit and re-lock. This means the safety device never has to be a barrier to legitimate access; it’s released deliberately, by key, rather than permanently fixed in place.

NSW & National Window Safety Compliance

Each year, more than 50 children fall from windows or balconies in Australia. Since 13 March 2018, NSW law has required strata buildings and owners’ corporations to install window safety devices on all common property windows, restricting openings and meeting the Industry Code of Practice for the Protection of Openable Windows (ICP005) testing specification.

The DS259 is designed to support compliance with this requirement on double hung windows. As with any window safety device, installers should test the completed installation using a certified testing device to confirm compliance, in line with manufacturing specifications and fitting instructions.

Kit Options — Single Window Kit vs. Bulk Trade Pack

The DS259 is available two ways:

• Complete kit — suits one window; the right option for a single-property owner or a one-off retrofit.
• Bulk trade pack — restrictor bars only, for pairing with the DS255 Sliding Window Limiter, sold in packs of 20; the right option for a trade installer working across a multi-dwelling building.

Installation & Maintenance

Because the DS259’s body is key-lockable and removable, cleaning or maintaining the window doesn’t require permanently disabling the restrictor — release it deliberately with the key, then refit once the job is done.

What channel width does the DS259 suit? 

Channels under 19mm wide — confirm this against the window before ordering, as it’s a specific compatibility constraint rather than a general guideline.

Is the DS259 suitable for older double hung windows? 

Yes — it’s ideal for windows manufactured before 1985 and for established dwellings that need window restriction retrofitted to existing frames.

Can the DS259 be removed for cleaning? 

Yes. The body is key-operated and fully removable, so it can be released for cleaning or maintenance and then refitted and re-locked.

What’s the difference between the single kit and the bulk trade pack? 

The complete kit suits one window and includes everything needed for a single installation. The bulk trade pack contains restrictor bars only, for pairing with the DS255 Sliding Window Limiter, and is sold in packs of 20 for multi-dwelling installations.

Does the DS259 meet NSW window safety compliance requirements? 

The DS259 is designed to support compliance with NSW’s window safety device requirements on double hung windows, including the ICP005 testing specification. Installers should test the completed installation using a certified testing device to confirm compliance.

How is the DS259 different from the SS0006 or DS255? 

The DS259 is purpose-built for double hung windows specifically. The SS0006 (now discontinued, replaced by DS255U/DS255) and the DS255 are universal cable restrictors suited to a broader range of window types. The DS259’s bulk trade pack is designed to pair directly with the DS255.