The Behringer UB-Xa is a polyphonic synthesizer inspired by the classic Oberheim OB-Xa. It features 12 voices and a 49-key keyboard. It offers a wide range of parameters including oscillators, filters, and envelopes. It also includes effects, modulation options, and a sequencer. The UB-Xa aims to offer a faithful recreation of the iconic OB-Xa sound with modern enhancements.