Man of Kent,  Not sure about a 'wrist band' but I would suggest that you have the Necklace. Then !! it will Always be there, for You, when you need it. -- As with your Mobile Phone, Always ON !! Our NHS Nurse, said we both should have one, but as we both keep our mobile phones On, We feel safe.
Two months ago, a friend of ours, was stuck in her bath and her mobile phone was out of reach. She was held in the bath for approx: three hours, before she could manage to get out.
My daughter also has had a fall in her garden and had to crawl indoors to reach her phone. My Eve too has fallen in the garden and I have been in my computer room. Accept these as a Warning!!  Be Safe, at All Times.

I have just looked up the Information that I have.
"The base unit has a 'Button' and the Pendant' has a button, the pendant can be worn around the neck, or on your wrist. Either of these two buttons will activate a call to  the 'control centre' to talk and obtain the assistance you need. -- Two key holders are required, these may be friends or neighbours. I hope this information, is of help to you.