The Chamber-View Company introduced a safety accessory for the shotgun market.  This bright orange device fits into the chamber, through the ejection port, of nearly any shotgun.  It provides immediate visual recognition that the firearm has been rendered safe.

The device is currently being sold by Beretta USA and will also be sold through Brownells.  Beretta is selling them for $9.95.  It is made of 100% silicone.