The Fundus Sound™ XM Intrauterine Sound is used in place of a reusable silver malleable or stainless steel sound. The Fundus Sound is used to gauge the depth and position of the uterine cavity. It is also helpful with the placement of IUDs and the verification of the intrauterine position and length for HSG procedures. The proximal portion of the sound is 3.5 mm in diameter tapering to 2.5 mm at the distal portion with a tip of 2.9 mm. It is a sterile, disposable, single-use only device.