German inventors have developed the world's first wristband that can detect if a drink has been spiked with date-rape drugs.
Inventors Kim Eisenmann and Sven Häuser were inspired to come up with the bracelet when a friend of Kim's was assaulted after her drink was spiked at a party.
The Xantus Drinkcheck Armband, which has gone on sale in German healthcare shop dm-drogerie markt , resembles the wrist tags clubbers and festival goers are given on the door and, the inventors say, can act as a deterrent as well as a test.
Common date rape drugs such as gamma-hydroxybutyrate (GHB) and Rohypnol are colourless, tasteless and virtually impossible to detect.
Victims can black out within 30 minutes with symptoms usually lasting for several hours. They will often not remember anything of the incident when they come round.
To test if a drink has been spiked, people simply dab a couple of drops on the Xantus bracelet and wait two minutes. The wristband will turn blue if GHB is present.
Every year in the UK, hundreds of people are thought to be victims of drink spiking.
Many incidents go unreported because the victim does not remember or feels embarrassed.
While drink spiking is most commonly associated with sexual assault, theft - and even misguided practical joke - can be a motive.
Kim and Sven said they had "have made it our mission to make celebrating safer and reduce the number of knocked-out victims".
"In addition, we want to make the (young) people understand that KO (knockout) drops can occur anywhere and at any time, which is why a sensitive approach to this issue is very important. Increased awareness and awareness clearly helps prevent the use of KO drops."