It has a unique smooth operating mechanism that restricts the initial window opening to 100mm in compliance with BS 8213, Part 1: 1991 ‘Code of Practice for Safety in Use and in Cleaning’. and BS 6375, Part2: 1987 ‘Strength of Restricted Opening’.

The mechanism requires some dexterity and two handed operation, giving added protection to children. An automatic reset facility also ensures safe operation at all times.