The antenna has efficiency at 20m and be an S unit less in performance at the 40m and 10m ends. You use a non-resonate length of wire for the driven elements typically 29′ 35.5′ or 41′ and optionally a 1/4 λ wire for a counterpoise. It is designed to wind the attached wires onto the device to store it as a small compact unit. 

Product Description: The QRPGuys 40m-10m UnUnTenna Plus is a compact portable wire antenna with a built-in tuner for backyard or portable SOTA use. It is similar in design to our UnUnTenna but this device also contains a tuner. 

The tuner section is based on the circuit designed by Lofgren W6JJZ also incorporating the Dan Tayloe (N7VE) SWR led indicator. The circuit was first designed for the Norcal QRP Club. It is rated at 10 watts PEP and uses an integral 9: 1 voltage balun that matches your unbalanced 50 ohm impedance input to a 450 ohm impedance unbalanced long wire.