Just what I wanted,&Very speedy delivery I appreciated the fair price

This is a neat lightweight gadget,v easy to use.I am happy to think that I will be found quickly if I fall indors or out.Idid have some difficulty ordering,I only wanted 2 alarms.the site wanted me to have 20! Had to get a grand child to help.I wouuld have preferred 2 different colours.I would like to know how often to test & what batteries to get .wherefrom & how to fit them if necessary.

Mrs Domb