This Lampholder has Push Wire terminal and not screw type. Therefor the wire needs to be either soldered or have ferules fitted.
The main body is snapped into the cap so stops the need to twist the wires. However please not that once the body is snapped into the cap it cannot be removed without damage.
The cap or bottom part has a 10mm female Base to connect to the lamp fixing.
Comes complete with a shade ring for a lamp shade with a 30mm diameter hole.