To the mobile presenter, weight is not everything. The size or volume of the projector as measured in cubic inches is a major factor in mobile convenience. Size varies considerably in this category. As in the weight category, the smallest product is the Compaq MP-1600 at a mere 187 cubic inches. At the other end of the spectrum is the Sony PX1 at 524 cu. in. The Sony, at double the weight of the Compaq, is almost three times its cubic inch volume. Thus the bulk of the package can be even more important than the weight of the unit.