Germans where well known for booby traps but this was a common practice of US forces too. 
Airborne and infantry units where using this type of wire to defend themselves. 
Seen in Saving Private Ryan to defend the city at the end. 
These Tripwire are from stocks dated 1943 and 1944. The type I is believed to be an early type (42) with nail fixation. Later type II and III (different wood design) will come with a clip, more practical and probably less expensive. 
Please indicate which type you are looking for in you order.