BBC Education and Social Policy Correspondent
A device designed to move on would-be criminals has been updated so as not to discriminate against the young.
But it is still being criticised by civil liberty campaigners.
The Mosquito emits a high-pitched sound and has been designed for use in potential crime hotspots such as subways and underground car parks.
The idea is that the noise it produces is so annoying that criminals will not want to hang around.
The Mosquito Mark 4 is a new version of the original Mosquito launched in 2005 - which was criticised for targeting only young people.
That version emitted a noise at such a high frequency that it was usually only audible to those under the age of 25.
Over 3,000 have been sold for use in the UK. Many have been placed outside shops, fast-food outlets and transport hubs - places where owners feel groups of unwanted youths are gathering.
However, their use has led to a national campaign - backed by the Children's Commissioner, the National Youth Agency and Liberty - calling for them to be banned.
They argue that even if the devices cause no damage to hearing they are an unfair attack on young people's human rights.
The makers, Compound Security Systems, have come up with a solution - a Mosquito which is annoying whatever people's age.
The new Mark 4 has an additional setting which allows the user to lower the frequency enabling the sound to be heard by people of any age.
The sound is emitted at 100 decibels - according to its inventor Howard Stapleton, it does not have to be loud to move people on.
He said: "It is quieter than a child playing the violin. What makes it appear loud is the fact that it is going on and off four times a second. That's what makes it very annoying."
'Buzz off' campaign
The new Mosquito, which went on sale last month, has already been selling well abroad.
According to the company, a major chain of hotels in Canada sees them as a way to keep homeless people out of their car parks.
In the UK, it is understood that one police force is about to start testing its Mosquito in an underpass favoured by muggers. A national car park chain is also said to be interested in trying the device out.
The "Buzz Off" campaign targeting the "anti-teen" device continues, with several councils in the UK banning its use.
There are now calls for the authorities to look at regulating against the new version.
Shami Chakrabati, Director of human rights group Liberty, said: "I think we need urgent research and regulation by the authorities. It's not going to stop determined criminals.
"It could cause damage to the rest of us and certainly make our lives a bit of a misery."
There is currently no specific legislation against the Mosquito.
According to the Local Government Association there are a number of ways currently being used to disperse potentially anti-social groups including talking CCTV and playing music.
A spokesman told the BBC: "So called 'Mosquito' deterrents could break the law but only if they're deemed to be causing a nuisance.
"If a council thinks there is a nuisance, either because they've received a complaint, or have detected it themselves, they have a duty under nuisance laws to investigate it."
On sale for less than £500, the sound of the new Mosquito has the potential to become annoyingly familiar - whatever your age.
6 months ago