The Topp ACK4 (ACK42) chain actuator is a high-quality product featuring 300N of traction/thrust force and a double link articulated stainless steel chain.  It’s enclosed in a die-cast aluminium case, making this a durable product, particularly well-suited for high use areas like schools.

Available in standard White, Silver, and Black colours as standard, but also available unfinished, and ready to apply your own powered coat finish.

As this chain drive has a sealed motor unit and is IP55 rated, the ACK4 (ACK42) can be used in areas where there is a risk of rain ingress.

The ACK4 actuator is also particularly popular in conservatories and orangeries.  Combined with a temperature control panel and rain sensors, these will manage the temperature automatically all day without the worry of rain getting in when you are out of the house.

We have 1000’s of these actuators in stock in the full range of colours along with the required control options.


With a variety of brackets available the Topp ACK4 (ACK42) chain actuator can be mounted on almost all types of windows with easy opening adjustment in 50mm increments. A single actuator is usually suitable for windows up to 1500mm wide.  For larger widows and vents a synchronous variant of the ACK4 (ACK42) can be purchased, allowing the use of two units in tandem.

Control Options

The ACK42 is a 230V AC actuator, giving you a wide array of control options like a Touchpoint Switch and Remote

Further Reading

If you’d like to know more about the ACK4, then read our ACK4 Product Focus article for a closer look at the motor and its specs.  If you’re looking for a replacement for an existing window actuator, then take a look at our Replacing an ACK4 (ACK42/ACK44) Window Opener guide.

Additional information

Stroke (mm)

Selectable, 100, 150, 200, 250, 300, 350, 400

Max Force (N)


Supply Voltage


Max Current (amps)


Max Speed (mm/s)


Window Types

Bottom Hung, Centre Pivot, Rooflight, Side Hung, Skylight, Top Hung

IP Rating




Black, Silver (RAL 9006), White (RAL 9010), Custom

Download PDF's

TOPP Chain actuator ACK4 details

TOPP Chain actuator ACK4 pdf instructions

TOPP Chain actuator ACK4S pdf instructions

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