You will always have the right duster for every purpose straight away the static charge doesnt stir up the dust but attracts it magnetically soft and gentle to furniture the small duster is ideal for keyboards the mid size duster is good for shelves etc that are higher and for hard to reach places the extendible duster is ideal for stairways high shelves and cupboards up to a height of 280 m size small 26 cm mid sized 56 cm extendible 96 110 cm