Images show the following:
Finishes: Hand Antiqued Brass, Unlacquered Brass, Polished Chrome, Lacquered Brass. 
Back Plates: Passage, Keyed, Privacy (Turn Piece $10).
 
Sold by the pair with 5/8" screws.
Passage and Privacy (Tube) Back Plates are compatible with pre-bored doors.
Keyed and Privacy (Turn) are not compatible with pre-bored doors. 
Privacy (Turn) Note: One plate has turn piece ($10) and one has key hole for emergency access.
 
NOTE: Locks and Latches are sold separately (See Below)