This study aims to compare the efficacy and safety of both types of lasers, Holmium MOSES and TFL, in management of kidney stones requiring treatment.

The prevalence of kidney stones has been increasing over the last two decades with lifetime recurrence risk reported to be as high as 50%. Holmium lasers are nowadays considered the "gold standard" for treatment of urinary tract stones.

Recently, the holmium laser urology platform from Lumenis has been updated to include a new technology called MOSES, which provides improved energy delivery of the laser to treat the stones, reduces migration of the stone during the procedure, and limits potential collateral tissue damage.

A new generation of lasers has evolved due to the advances in laser fiber technology, leading to the development of the Thulium Fiber Laser (TFL). TFL can operate within a large range of energy, frequency and pulse duration settings. The small fiber size is one of the main advantages of TFL, as it allows better endoscope performance through easier deflection and bigger working channel space. Furthermore, it produces small stone fragments and better dusting capabilities compared to the standard Holmium laser when adjusted on the same power settings.

This study will compare the efficacy and safety of Holmium MOSES and TFL in management of kidney stones requiring treatment.

Inclusion Criteria:

1. 18 years of age and over at the time of enrollment.
2. Patients referred with single kidney stones of 10-20 mm in its largest diameter, or multiple stones involving a single calyx.
3. Written informed consent to participate in the study
4. Ability to comply with the requirements of the study procedures

Exclusion Criteria:

1. Patients with ipsilateral distal ureteral stones or stricture.
2. Stone size > 20 mm or multiple kidney stones in different calyces.
3. Previous shock wave lithotripsy (SWL) treatment for the same stone.
4. Participants with active urinary tract infection until appropriately treated
5. Uncorrected coagulopathy (anticoagulants or blood thinners which cannot be withheld before surgery).
6. Pregnancy.
7. Participants with preexisting conditions, which, in the opinion of the investigator, interfere with the conduct of the study.
8. Participants who are uncooperative or cannot follow instructions.
9. Participants who lack the capacity, or cannot speak English, in order to provide free and informed written consent.
10. Patients with solitary kidney.