A vibration transmitting member for use with a clamp member. The vibration transmitting member provided with vibration from an ultrasonic transducer and including: a body having a distal portion with a surface and an opposite surface, the body further having a proximal portion； wherein: the body extending along a longitudinal axis extending from the proximal toward the distal portion, the surface opposes the clamp member and having a ridge extending along the longitudinal axis, the ridge extends toward the clamp member in a thickness direction more than other portions of the surface, the opposite surface opposes the surface and having a projection extending along the longitudinal axis, the projection protrudes more than other portions of the opposite surface in the thickness direction, and a maximum thickness of the distal portion is smaller than a maximum width of the distal portion in a width direction perpendicular to the thickness direction.
