Heritage Fastener Locking- Satin Chrome

Excellent product - the best choice for a period property.
Much like the fasteners of my long-distant youth in a Victorian townhouse, these are a modern version of the Fitch fastener that suit a period property much better than the other sash fasteners.
Standard Fitch fasteners are the only ones that appear to be approved by the police but are not accepted by insurance companies, who require removable key locking. Installing these means we are finally covered for burglary.
They cost twice as much as the other kinds but are more than twice as good.
Highly recommended.