Introduced in Wairarapa last year, six have already been issued to people with autism or dementia.
The tracking device is similar to that used to locate kiwi, with a pendant or watch transmitting a signal which can be detected by a radio tracking unit using a directional aerial.
The pendant is waterproof so it can be worn in the shower or bath and can be secured so the wearer can not take it off. It emits a signal which can be detected up to 3km away, or as far as 10km from a hill.
"It gives the carers peace of mind. They know if the family member goes for a walk, that's it."
One elderly Masterton woman had been known to walk about 6km into town before being found.
"It's amazing the distance they can cover in a short time."
The information gathered on the wearer's assessment form also provided searchers with invaluable information as to their habits, Mr Milligan said.
"Because we get to know the people and their different traits, we can alter our search pattern accordingly."
Often autistic people might see things in the surrounding area they liked, such as a truck or a fire engine, while dementia patients might try to walk back to their former home or to find a relative.
The importance of such tracking tools had been highlighted by several cases across the country of elderly people dying or contracting hypothermia after becoming lost overnight.
It was likely they could have been found in as little as 45 minutes, had they been wearing a tracking pendant, Mr Milligan said.
During a recent training exercise in Masterton, two volunteers carrying the pendants had been found within an hour and a half.
In January last year, elderly woman Roma Roberts wandered from Metlifecare Retirement Village in Masterton, sparking a substantial 19-hour search by rescue services and the public before being found hunkered down in the laundry of a neighbouring property.
About 18 Wairarapa Search and Rescue volunteers have been trained to use the tracking equipment and the system can be used across much of New Zealand.
Search and Rescue currently have two radio receivers based in Masterton and are seeking funding for a third, which would be based in Greytown.
The pendants are available for a donation of $290, plus a $10 per month maintenance fee which includes batteries and servicing.
In certain cases the cost of the pendants may be sponsored, depending on individual circumstances.
-Anyone interested in applying for a pendant should contact Alzheimers Wairarapa, Autism New Zealand or Autism Wairarapa Charitable Trust.
