The Pro-Twist by Jackloc Window Restrictor is an incredibly strong cable restrictor, with a push and turn locking release mechanism. The restrictor can fit most window sizes and types, including uPVC, Timber and Aluminium. The push and turn bullet provides an easy way to fully open your window when required. The Pro-Twist by Jackloc is incredibly strong, with a reinforced cable, security screws and a heavy-weight body. Each product is individually tested in the manufacturing process to hold a force of 3,600 newtons (800lbs). The product comes with four security screws to help keep homes safe
 
Excellent for Flight Risk Children as well
10 cm (4" opening)
Push in, turn and hold design makes it very difficult for little ones to figure it out
YouTube Video https://youtu.be/_tRVTQ3H1CE