The Pyramid of Light of the Guardians of the Flame brings high vibrational light that harmonises the environment. It brings back balance and dynamism and will generate an environment supportive to growth and transformation. 
Place it in rooms where there is activity such living-room, office, classroom... The wonderful influence of this pyramid will stimulate all environments, beings and objects allowing harmonious relationships. It improves your progess, ability to change and concentration. Try to place the Pyramid as high as possible in the room.
 
An explanation to the sizes: 
The Large model is suitable for BIG spaces, 
the Medium model suits normal to small spaces,
and the Small model is especially made to be used in energetic healing sessions.