Prospective, multi-center, non-randomized, open label, clinical study intended to provide data to demonstrate safety and performance of the SoundBite Crossing System XS Peripheral.

The CaTO-PAD study includes a below-the-knee (BTK) sub-study (CaTO-BTK)

Inclusion Criteria:

1. Scheduled for interventional treatment of de-novo lesion(s) of the following native arteries:

   1. CaTO-PAD: infrainguinal
   2. CaTO-BTK: infrapopliteal

2. Have at least one chronic total occlusion (CTO) with no flow observed in the distal lesion except the flow from collateral circulation

3. Presenting with the following:

   1. CaTO-PAD: claudication or CLI (Rutherford Clinical Category 2-5) of the target limb
   2. CaTO-BTK Sub-Study: - Category 4 or 5 only for CaTO-BTK Sub-Study CaTO-PAD: claudication or CLI (Rutherford Clinical Category 2-5) of the target limb

4. Age of > 18 years

5. Have been informed of the nature of the study, agrees to participate, and has signed the approved study consent form

6. Target lesion calcification is at least moderate by PARC definition (see Section 15)

7. Target lesion is refractory as demonstrated by a failed attempt with a guidewire

Exclusion Criteria:

1. Any medical condition that would make subject an inappropriate candidate for interventional treatment as determined by the Investigator, including the following:

   1. Glomerular filtration rate <30 ml/min
   2. Mortality expected within 30 days

2. Already enrolled in an investigational interventional study that would interfere with study endpoints

3. Target lesion is crossed intraluminally with a conventional guidewire

4. Treatment of an inflow lesion prior to target lesion treatment results in no reflow, thrombus formation, abrupt closure, distal embolization, dissection or perforation requiring treatment

5. Women who are pregnant or breastfeeding