The Rounded-Edge 4-Wire Basket has a rounded-edge wire that is manufactured to minimize ureteral trauma during stone manipulation. The Permaform Wire Construction is manufactured to keep the basket symmetrical while capturing the stone even when it is difficult. Its wire's excellent strength is manufactured to retrieve stones reliably and grasp them securely. These come in a variety of configurations and sizes. The sheaths are 2.4F, 3.0F and 4.5F. 20 mm is the size of the basket used for retrieving larger stones. A 16 mm basket is used to help preserve the capability of retrieval in tight ureters. These come without tips or with 5 cm filiform tips.