ReconRobotics Inc., said sales of its tactical micro-robots passed 4,000 units, making it the world's second largest producer of military and police robots.

Recent U.S. sales include Throwbot XT and Recon Scout XL micro-robots to police in Michigan, Texas, Illinois, Georgia, New York and California. The robots were also sold to Britain and the Netherlands.

"When we came on the scene in 2007, all military and police robots were large and complex and were operated only by trained experts," said Alan Bignall, president and chief executive officer of ReconRobotics. "Our vision was radically different: give warfighters and SWAT operators an incredibly simple, personal system that weighed one pound and enabled them to remotely deploy video, infrared and audio sensors to reveal hidden threats.

"What we are most proud of is the countless lives these 4,000 deployed systems have saved over the last six years."

In first place for sales of micro-robots is iRobot, which entered the market six years before ReconRobotics.