IP means International Protection and is used in connection with the material’s protection class. IP is stated with 2 numbers (e.g. IP20) to say how safe the material is in connection with water penetration and the penetration of dust and solid objects. Materials are divided into protection classes that state – partly the protection of the material itself against penetration of foreign objects and water – and partly the protection of people who touch dangerous parts. The first number always states the degree of protection against foreign objects penetrating the material, but at the same time, it states a certain smallest degree of protection of people who touch dangerous parts. The second number states the degree of protection from water penetrating the material.
Yes (except for those with integrated LED) if the size of the light bulb allows it to be fitted in the lamp. It is the physical size and not the Watts in the light bulb that determine whether you can fit it in the lamp when it comes to energy-efficient light bulbs.