EXHIBIT 22.1

List of Subsidiary Guarantors and Affiliates Whose Securities Collateralize

Securities of Nine Energy Service, Inc.

Each of the subsidiaries of the Company listed in the table below (each, a “Subsidiary Guarantor”) is a guarantor of the Company’s 13.000% Senior Secured Notes due 2028 (the “Notes”), and the equity interests of each Subsidiary Guarantor have been pledged as collateral for the Notes and the guarantees thereof.

Name						State or Other Jurisdiction of Incorporation or Organization
CDK Perforating, LLC						Texas
Crest Pumping Technologies, LLC						Delaware
Magnum Oil Tools GP, LLC						Texas
Magnum Oil Tools International, LTD						Texas
MOTI Holdco, LLC						Delaware
Nine Downhole Technologies, LLC						Delaware
Nine Energy Service, LLC						Delaware
RedZone Coil Tubing, LLC						Texas