IEC Protection Classes for Electric Appliances

IEC protection classes differentiate protective-earth connection requirements for devices.

Class 0 - non-earthed product, illegal for sale in UK.
Class 1 - connected to "earth" by an earth conductor.
Class 2 - double-insulated, labelled with square inside a square

A-weighted Decibels (dbA ratings)

A-weighted decibels, abbreviated dBA or dBa, measures loudness of sounds whereby the decibel level of sounds at low frequencies are reduced, since the human ear is less sensitive to those sounds (below 1000Hz). It is often used to describe the loudness of fans e.g . microprocessor cooling fans or bathroom extractor fans. 25 dBA is a human whisper in a quiet room.

FB Keys

FB keys are Fire Brigade keys. They are used for areas where the fire brigade or other service personnel may need to get access to: communal areas, cupboards and access points.

What is an IP Code?

IP Code refers to the Ingress Protection Rating of some device, regarding the degree of protection against intrusion of solid objects. It is meant to offer a higher degree of precision to terms such as "waterproof". The IP rating consists of two digits: the first refers to penetration by solid particles and the second by liquids. A second digit of 4 means the device is protected against splashing water, but not against water jets, and certainly not powerful water jets. It certainly can't be immersed (to any depth). The relevant standards body is the IEC (International Electrotechnical Commission).