In this demonstration paper, we present a multi-radio MAC protocol and a prototype sensor node platform which supports dual frequency bands of operation. The multi-radio MAC protocol combines the advantages of both high and low frequency bands to give an energy efficient performance with high throughput and low latency in several applications. Our prototype supports spectrum agility, which is becoming important due to ever crowding spectrum. Besides demonstrating the improved performance metrics and spectrum agility support, we will also present the flexibility provided by our MAC protocol.