EXHIBIT 22.1

List of Subsidiary Guarantors and Affiliates Whose Securities Collateralize Securities of Nine Energy Service, Inc.

Name	Jurisdiction
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