The type required will depend on how big the sump is. If you have a tight space, a tube float is offered, as there is no space for a lead float to be free. If you have a larger sump, a lead float may be the better option, as the float has space to rise and fall with the water level. These pumps are often found at the lowest level of a property, garages, lift shafts, and generally, any area that is prone to flooding.