The chopper system for the Spallation Neutron Source (SNS) provides a gap in the beam for clean extraction from the accumulator ring. It consists of a pre-chopper in the low energy beam transport and a faster chopper in the medium energy beam transport (MEBT). It took several iterations to develop a working design with the required parameters. In this paper we describe the latest design of the MEBT chopper deflector and give results of the experimental verification of the chopper effectiveness, the gap cleanliness and the measured rise time. The effect on the losses is discussed as well.