Presenting Unit 04 One of the most important contributions to the Unit Portables system of functional and must have-units. A protective, padded sleeve specifically for an iPad or other tablet computer. Available to purchase separately or in a package with Unit 01-03. Designed like a stylish mini version of Unit 01, Unit 04 also features the built in handle design, allowing you even more portability. Attach to the inside or outside of Unit 01 or simply use on its own.