Related Party Transactions	9 Months Ended
Sep. 30, 2019
Related Party Transactions
Related Party Transactions	10. Related Party Transactions From time to time, we rent an airplane under dry-lease from a company owned by a member of Cactus LLC. These transactions are under short-term rental arrangements. During the three months ended September 30, 2019 and 2018, expense recognized in connection with these rentals totaled less than $0.1 million and $0.1 million, respectively. For the nine months ended September 30, 2019 and 2018, expense recognized in connection with these rentals totaled $0.2 million and $0.1 million, respectively. As of both September 30, 2019 and December 31, 2018, Cactus LLC owed less than $0.1 million to the related party, which is included in accounts payable in the consolidated balance sheets. We are also party to the TRA with certain direct and indirect holders of CW Units, including certain of our officers, directors and employees. These TRA Holders have the right to receive 85% of the net cash savings, if any, in U.S. federal, state and local income tax and franchise tax that Cactus Inc. actually realizes or is deemed to realize in certain circumstances. The total TRA liability as of September 30, 2019 was $220.9 million. The estimated annual amounts and timing of this liability is presented in Note 8. Distributions made by Cactus LLC are generally required to be made pro rata among all of its members. During the nine months ended September 30, 2019, Cactus LLC distributed $9.9 million to Cactus Inc. to fund the 2019 TRA liability payments and estimated tax payments and made pro rata distributions to its other members totaling $5.9 million. For the nine months ended September 30, 2018, Cactus LLC made a $3.8 million distribution to Cactus Inc. to fund its quarterly estimated tax payments to the IRS and made a pro rata distribution of $5.8 million to its other members. These distributions were funded by cash flow generated from operating activities. Prior to our IPO, Cactus LLC made a cash distribution of $26.0 million to pre-IPO owners on January 25, 2018. The purpose of the distribution was primarily to provide funds to these owners to pay their federal and state tax liabilities associated with taxable income recognized by them for periods prior to the completion of our IPO as a result of their ownership interests in Cactus LLC.

10. Related Party Transactions

From time to time, we rent an airplane under dry-lease from a company owned by a member of Cactus LLC. These transactions are under short-term rental arrangements. During the three months ended September 30, 2019 and 2018, expense recognized in connection with these rentals totaled less than $0.1 million and $0.1 million, respectively. For the nine months ended September 30, 2019 and 2018, expense recognized in connection with these rentals totaled $0.2 million and $0.1 million, respectively. As of both September 30, 2019 and December 31, 2018, Cactus LLC owed less than $0.1 million to the related party, which is included in accounts payable in the consolidated balance sheets.

We are also party to the TRA with certain direct and indirect holders of CW Units, including certain of our officers, directors and employees. These TRA Holders have the right to receive 85% of the net cash savings, if any, in U.S. federal, state and local income tax and franchise tax that Cactus Inc. actually realizes or is deemed to realize in certain circumstances. The total TRA liability as of September 30, 2019 was $220.9 million. The estimated annual amounts and timing of this liability is presented in Note 8.

Distributions made by Cactus LLC are generally required to be made pro rata among all of its members. During the nine months ended September 30, 2019, Cactus LLC distributed $9.9 million to Cactus Inc. to fund the 2019 TRA liability payments and estimated tax payments and made pro rata distributions to its other members totaling $5.9 million. For the nine months ended September 30, 2018, Cactus LLC made a $3.8 million distribution to Cactus Inc. to fund its quarterly estimated tax payments to the IRS and made a pro rata distribution of $5.8 million to its other members. These distributions were funded by cash flow generated from operating activities. Prior to our IPO, Cactus LLC made a cash distribution of $26.0 million to pre-IPO owners on January 25, 2018. The purpose of the distribution was primarily to provide funds to these owners to pay their federal and state tax liabilities associated with taxable income recognized by them for periods prior to the completion of our IPO as a result of their ownership interests in Cactus LLC.