Section 876.4650 - Water jet renal stone dislodger system(a)Identification. A water jet renal stone dislodger system is a device used to dislodge stones from renal calyces (recesses of the pelvis of the kidney) by means of a pressurized stream of water through a conduit. The device is used in the surgical removal of kidney stones.(b)Classification. Class II (special controls). The device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to § 876.9 .48 FR 53023, Nov. 23, 1983, as amended at 63 FR 59228, Nov. 3, 1998