Securikey Heavy Duty Polycarbonate Quarter Dome Ceiling Security Surveillance Convex Mirror for Institutions. The quarter dome should be corner mounted in cells & at right angle corners to provide 90° vision & prevent surprise attacks or collisions. This mirror is designed so that officers, warders & nurses are able to view the inmate/patient to see if it is safe to enter & that nobody is concealed behind the door. The mirror is also used in right angled passageways in prisons, institutions & justice courts. This is to prevent attacks, avoid collisions & surveillance of passageways. Virtually indestructible & unbreakable, mirror quality polycarbonate face Rock resistant, Bullet resistant, resistant to repeated blows, Shattering Spalling Pure silver reflective coating Powder coated steel frame with unique tamper-proof design Recessed, tamper-proof fixings High heat resistance to 240 degrees Extra Wide Field of Vision Especially good for right angled passageways Brightest of reflection Easy to Install Ideal for surveillance by warders, nurses etc Can be used in conjunction with CCTV to enhance effectiveness & safety