Acrylic domes are made of durable shatter resistant acrylic and PETG is a copolyester that is an amorphous thermoplastic. PETG offers excellent impact resistance, and is more lightweight than polycarbonate. Provides 90, 180, and 360 degree viewing for ceilings and walls. Excellant clarity. Ideal for retail, warehouse, office or public areas. One inch of mirror diameter equal one foot of panoramic viewing area. Easy to install, mounting hardware supplied where required. 360 degree dome for a 4-way intersection and can be suspended from ceiling, 180 degree dome for 3-way T intersection can be mounted on wall or ceiling, and 90 degree dome for 2-way L intersection can be mounted on wall of ceiling.