A device for finding and marking the point of contact between the center of an ultrasound probe with skin of a patient and method of use thereof is disclosed. The device includes a block member having a handle. The block member includes a protrusion capable of making an indentation on skin of a subject. A ring member defining an aperture is configured to guide the block member into contact with skin of a subject such that the protrusion forms an indentation on a patient's skin. The indentation serves to mark the location which may then be used to identify an injection site (e.g., epidural) or other medical treatment procedure location. The injection or treatment location is found using a transducer or ultrasound for which the ring member is adapted to receive in advance of the block member.
