The idea behind the Plastimont range is to give the customer a degree of flexibility over which threaded insert to use to create the desired fastener.
Plastimont is a kit for customer assembly.
The customer Insert's the fastener of choice, male or female hexagon type, in their material of choice, into the body and fits the cap (if required) to finish.
The insert will be a tight fit to secure it, and idealy should be pressed in.