I am selling a DC power supply 2 x 18V2A, the transformer has a lead-out center. Now it is connected in the box so that you can change the polarity of the 18V +- output with the help of two buttons. Please contact me via the Bazoš form, or by e-mail inzeratyja@gmail.com, or by phone at 0905950410, I do not answer SMS. Thank you for understanding. Joseph