Door chain

[3] Door chains are mainly intended to allow a person inside a structure to open the door slightly for purposes of communicating with individuals outside or exchanging small objects through the door while still preventing the individuals outside from gaining unauthorized access into the structure.

Door chains normally come equipped with very short screws which easily rip out.

Door chains are often installed improperly, making them easily subjected to a number of attacks.

UPVC/PVCU front doors are generally unsuitable for retrofit security devices.

Not only is the material not strong enough to support devices fitted with steel screws unless secured into the internal metal framework, but such changes to the original design may invalidate an existing warranty or possibly damage the integral locking assembly.