All door knobs are supplied in pairs with spindles and fixings. Locks and latches are ordered separately to suit your door.
Door knobs require a deeper latch than standard handles to prevent your hands from being trapped between the door knob and door frame when you close the door towards you. For this reason, we recommend a 102mm (4-inch) door latch, however, you will need to make sure that the door can accommodate this size latch first. A 76mm latch can work on some door knobs but we do not recommend a 64mm latch or lock unless the door knobs are installed in the middle of non-rebated double doors.
For un-sprung door knobs, you will need a high-quality latch.
For information on lock and latch sizes please see FAQ 'What backset size do I need?'