Us Weight Plastic Stanchion Sign Holder with Plexiglass Covers for USW ChainBoss, Sentry & Sentry PLUS StanchionsShare your important message quickly with the US Weight sign holder. The sign holder perfectly fits on top of your US Weight ChainBoss, Sentry or Sentry PLUS stanchion and allows you to advertise wherever temporary or permanent signage is needed. This sign holder is not compatible with other stanchions. Promote specials or instruct consumer traffic through your queue using the plastic frame with a visual area of 8 inch x 10 inch. The frame accepts 8.