The Fido XT detectors use amplifying fluorescent polymers developed by ICx to detect the explosives. Unlike many electronic explosives detectors, this unit does not require any nuclear materials to perform and detects both particles and vapors without any modification to the basic unit. 

The Fido XT consists of a control unit and a separate sensor head unit that can be combined into a single portable device or used with a tether between the two components. In addition, the sensor head can be attached to a bench system or to a robotics system for automated usage without direct human interaction. 

The handheld unit weighs just 2.7 pounds including a Lithium Ion battery capable of powering the system for up to four hours at a time. The base unit is 9.8 inches by 4.8 inches by 2 inches and the sensor head is 3.5 inches by 3.5 inches by 1.5 inches. The system includes 3 foot and 6 foot long tethers out of the box and custom tether lengths are also available. The Fido XT detector includes both USB 1.0 and serial (RS 232) ports and provides 256MB of onboard memory in handheld mode. 

Fido XT devices can detect trace residue of explosive material on people resulting from either the construction or detonation of an explosive devices quickly and efficiently enough to use at checkpoints or in other situations requiring rapid testing of groups of individuals. It can also detect vehicles transporting explosive devices even if the device is not currently present and detect trace residue in baggage or cargo or mail. Its data collection capabilities also make it ideal for forensic investigations involving explosives. 

Fido XT is currently used as a screening method for visitors to the Statue of Liberty and the Olympic Games in Beijing. The device is also being tested for military applications in Iraq. Each Fido XT unit costs $21,000. 

TFOT has previously reported on a portable plastic explosives detector, a spray that helps detect trace amounts of explosives, and another spray that helps detect Urea Nitrate, a common homemade explosive. In 2006 TFOT reported on a new Israeli company which has developed a simple, and cost-effective pen-like device that can detect one of the most dangerous improvised explosives known to man - TATP.