Promoted by the manufacturers as "The smallest combined GPS and Laser Safety Alert System in the World", the Snooper S4 is a very small unit, roughly the size of a pack of 20 cigarettes. The unit includes an integrated 360 degree laser detector to warn of mobile laser speed enforcement devices and a GPS database system to provide advance warning of fixed speed enforcement devices and accident blackspots. The GPS database can also optionally be updated to include advance warning of school zones.
As the both the laser detector and GPS antenna are integrated within the main unit, it must be mounted in a position where it has "line of sight" to the outside of the vehicle. This can be achieved by using the provided velcro mounting strip to secure the unit on the dash top, or by securing the unit to the windscreen. Depending on the exact location used, rear laser detection may be reduced by the obscuring effect of the vehicle's seats or passengers. Operation may also be effected by the heat reflective front windscreen treatment now used by some vehicle manufacturers, although the unit's manufacturers now say that this issue has been addressed to an extent.
The unit uses an LED text display to provide visual warnings, and voice alerts which can optionally be changed to a warning piezo beep. Both alert systems indicate the type of hazard being approached and the display provides a distance countdown to the exact location. Information on the posted speed limit at the location is also provided.
The S4 can be used in conjunction with the S100 RLD remote radar/laser add-on module. This adds active radar detection to the device, resulting in it being able to detect handheld radar guns and portable mini GATSO cameras which cannot be detected as standard. The S100 RLD also includes a secondary laser detector.
The manufacturers also offer a re-radiating GPS antenna, which can be used in conjunction with the S4. This allows the unit to be mounted in a position where line of sight GPS reception cannot be achieved. Where this is the case, the unit's integrated laser detector will probably also not work, but this can be overcome to some extent (to at least give laser detecting in a forward direction) by the use of the S100 RLD.
The S4 includes an earphone socket, which can be used with an optional ear-piece, designed for use inside a motorcycle helmet.