The paper introduces the PHANTOM haptic interface, a device designed to measure and control the force exerted on a user's fingertip, enabling interaction with virtual objects. The device is a desktop mechanism that tracks the user's finger movement and exerts forces to simulate physical interactions. Key design principles include low mass, low friction, low backlash, high stiffness, and good backdrivability. The PHANTOM is based on three enabling observations: force and motion are crucial haptic cues, many interactions involve minimal torque, and a small workspace is sufficient for most interactions. Three necessary criteria for an effective haptic interface are free space feeling free, solid virtual objects feeling stiff, and virtual constraints not being easily saturated. The PHANTOM's mechanics involve a transmission between motors and the user's finger, with a passive three-degree-of-freedom gimbal to simplify programming and design. The device has been used to create various virtual objects and textures, and users have reported strong reactions to certain haptic experiences. The PHANTOM is currently in use in multiple research labs and is expected to advance in size and functionality.The paper introduces the PHANTOM haptic interface, a device designed to measure and control the force exerted on a user's fingertip, enabling interaction with virtual objects. The device is a desktop mechanism that tracks the user's finger movement and exerts forces to simulate physical interactions. Key design principles include low mass, low friction, low backlash, high stiffness, and good backdrivability. The PHANTOM is based on three enabling observations: force and motion are crucial haptic cues, many interactions involve minimal torque, and a small workspace is sufficient for most interactions. Three necessary criteria for an effective haptic interface are free space feeling free, solid virtual objects feeling stiff, and virtual constraints not being easily saturated. The PHANTOM's mechanics involve a transmission between motors and the user's finger, with a passive three-degree-of-freedom gimbal to simplify programming and design. The device has been used to create various virtual objects and textures, and users have reported strong reactions to certain haptic experiences. The PHANTOM is currently in use in multiple research labs and is expected to advance in size and functionality.