A surgical system is provided that includes a device body that has a working channel providing a pathway for an instrument, an extension adjuster engaged with the device body, the extension adjuster also including a stop. The stop is disposed a predetermined distance from the working channel such that the stop and the distal end of the working channel cooperate to define an effective working channel length. The instrument may be inserted through the working channel and protrude outwardly from the distal end of the working channel. The extent of the protrusion is limited by the effective working channel length whereby the stop prevents further insertion of the instrument.