The white-bone gentleman's lockback is a single D2 blade in smooth white bone, opened with a nail nick and held by a backlock.
At 2.95" of blade and 6.69" open, it is the dress-pocket Treebrand lockback.
Specifications
Type: Gentleman's lockback
Blade steel: D2
Handle: Smooth white bone
Opening: Nail nick
Lock: Backlock
Blade length: 2.95"
Overall length: 6.69"
MPN: 110813