Probably the most popular type of connection for bigger rental companies that are almost constantly on tour. The connection itself is carried out through two opposing types of fork ends, male and female, that are coupled together by safety pin that is secured by either safety clip or a nut. That means that you always connect one female end of the truss to the male end of the second truss piece and so on. Depending on the type of the fork truss structure both fork ends and size of the safety pin vary. Usage of hammer for placing the pin into the fork ends holes is allowed.
For more info click here