Police are encouraging people to attach bells to their wallets to deter pickpockets and thieves.
The Broadwalk Centre, in Station Road, Edgware, is working with the Metropolitan Police to distribute safety alarms to shoppers.
The bag bells can be attached to any wallet to alert owners to potential thieves while out shopping or in busy public areas.
They were introduced after a spike in people reporting picket pockets around Edgware. People can pick up their free bells from police stations or the Broadwalk Centre.