A faceplate which has a single screw, fixed in position and projecting from the exact centre of the face, is known as a "screw chuck". Sometimes they are supplied as a freebie with a multi chuck but it is better if you have an independent one. Screwchucks with a pointed small screw enable quick mounting of small blocks of wood - you can just screw the block on while the screwchuck is on the lathe. Screw chucks with larger parallel threaded screws require you to drill a pilot hole first but give a superior grip.
You can make servicable screw chucks yourself out of wood on your lathe! These are handy for holding such projects as wooden fruit, toy wheels or anything which can be held by a small central hole.