Designed for 1/4 and 3/8 inch thick glass and acrylic, most glass tanks from 30 to 125 Gal. & most acrylic tanks up to 36 inch long and 20 inch high. The inside magnet projects 1/2 inch beyond the outer magnet. This extended reach allows cleaning beyond the visible edge of trims and canopies. Other advanced features such as ergonomic grip, replaceable pads for glass and acrylic, large 2.5 x 3.75 inch cleaning surface set this product apart from all others. This Magnavore product features a one year warranty against defects in materials and workmanship. Huge performance at low cost!