My understanding is that the NRC views key-chain tracers as a novelty item and therefore is not permitted in the US. As far I know, all European countries do allow them, as they are sold openly, from several sources, so I do not believe product safety is at issue. There is a US based company that produces tritium markers for military and industrial purposes. US based private citizens (mainly CPF members) who have contacted the company have been told they cannot sell to individuals, that even those sold to legitiment industrial companies for safety markers, must be licensed to possess the markers and must register with the NRC the location of the markers. By the way there is a new X2 version of the traser, looks really cool. Pete