In this paper, the authors present a logical circuits design for approximate content matching implemented as Finite State Machines (FSM). As network speed increases the software based Network Intrusion Detection and Prevention Systems (NIDPS) are lagging behind requirements in throughput of so called deep package inspection - the most exhaustive process of finding a pattern in package payloads. Therefore, there is a demand for hardware implementation. Approximate content matching is a special case of content finding and variations detection used by \"Evasion\" techniques. In this research they will enhance the k-differentiate problem with \"Ability\" to detect a generalized Levensthein edit distance i.e. transposition of two neighboring characters.