From the members guide - http://www.cbsa-asfc.gc.ca/publicati...f5095-eng.html

"Note: If you have any commercial goods in your possession or baggage or on board the vehicle/recreational boat upon arrival in Canada or the United States, you may not use NEXUS in the air, land or marine modes of transportation. Commercial goods are defined as goods brought into Canada or the United States for sale or for any commercial, industrial, occupational, institutional or other similar use and include samples, tools and warranty repair parts.

Personal computers and similar items carried by NEXUS members for their own personal use while on business trips are not considered commercial goods."