Lockable safety lid for drinking glass, comprising inner layer of tampering indication substance

摘要

A drink can be easily tampered with when left unattended for a short while only. The safety lid can be attached to the top of a glass and locked with a key of an individual shape, only matching the particular lock. The lid is made of two separate chambers. Two substances, changing into a foam when they get in contact, are accommodated within the chambers, indicating a penetration of the lid with a needle.