The new Torus PowerBlock series is Toroidal Isolation transformers with compact footprints and rugged construction. PB 10: Suitable for mid-power AV systems, featuring isolation between outlet pairs Torus PowerBlock PB 5 and PB 10 are ultra compact and portable Toroidal Isolation Power Transformers, and the most affordable products in the Torus line-up. The compact footprint and rugged construction of PowerBlock models make them convenient for use in almost any situation. They look sharp on or near a component shelf, on any floor surface or can be located elsewhere when space is at a premium. Torus PowerBlock PB 5 & PB 10 models come with a replaceable fast acting fuse 5mm x 20mm on the input side of the unit. Torus PowerBlock models will shutdown if the internal unit temperature reaches excessive levels.