The DIGITRAX UR90 is the Infrared (IR) receiver unit. The UR90 looks similar to a UP5 and is mounted in the fascia of the layout. The UR90 is simply an addition to your existing LocoNet so no additional wiring is needed. For specs visit the product's webpage by clicking on the link below. As always call to see if you qualify for any additional discounts, and to check the accuracy of your order's weight. This unit lists for $45.