All about meThis Recessed Waterproof Storage Unit (350mm x 350mm x 100mm) is a perfect solution for storing toiletries in your bathroom without having external baskets it can be easily installed using any bathroom fixing adhesive.These units come in a variety of different sizes to accommmodate every bathroom size.The measurements provided are the external dimensions of the box. Need to know . External Dimensions . 350x350x100mm Internal Dimensions . 1600x350x180mm Provides a fully waterproof base for tiles . Easily installed using any bathroom fixing adhesive glued into position between stud work . Can be cut to required size with a hand saw . Designed for pre-wall installation to make excellent use of space otherwise lost