A Whittler is any pen knife with three blades--a large blade at one end and two small cutting blades at the other end. Typically they have two springs with each of the small blades having their own and the master blade using both springs.
Whittler Pocket knives have always been pricey. Because of their construction, they are labor intensive to make. The back springs have to be precise to make them work properly. Some manufacturers have used three springs instead of two to keep the cost down. They are not, technically, whittlers.
We recommend a KSF PocketSlip to keep your knife safe in your pocket for years to come.