Mirror for security

My friend has recently opened a branch of their convenience store in the city. They have been in this business for many years now they grow yearly by setting new stores. Anyway they asked me if I could refer them to a mirror store who sells convex mirror since their former store has moved out of town. They prefer getting convex mirror aside from surveillance cameras because the whole store can be seen with these mirrors. This way the attendant can monitor the events inside the room and they can call on the attention of the police when any incident is happening inside. I would want to help but I have not known any people who sell mirrors in the city so I told them to search online.