; (B) new roads and improvements to existing roads; (C) U.S. Border Patrol facilities and ports of entry; (D) aircraft, aircraft-based sensors and associated technology, vessels, spare parts, and equipment to maintain such assets; (E) a biometric entry and exit system; and (F) family residential centers. (b) Availability of border wall system funds (1) In general Of the amount appropriated in subsection (a)(1)— (A) $2,241,000,000 shall become available October 1, 2018; (B) $1,808,000,000 shall become available October 1, 2019; (C) $1,715,000,000 shall become available October 1, 2020; (D) $2,140,000,000 shall become available October 1, 2021; (E) $1,735,000,000 shall become available October 1, 2022; (F) $1,746,000,000 shall become available October 1, 2023; (G) $1,776,000,000 shall become available October 1, 2024; (H) $1,746,000,000 shall become available October 1, 2025; and (I) $1,718,000,000 shall become available October 1, 2026. (2) Period of availability An amount made available under subparagraph (A), (B), (C), (D), (E), (F), (G), (H), or (I) of paragraph (1) shall remain available for five years after the date specified in that subparagraph. (c) Availability of border security investment funds (1) In general Of the amount appropriated in subsection (a)(2)— (A) $500,000,000 shall become available October 1, 2018; (B) $1,850,000,000 shall become available October 1, 2019; (C) $1,950,000,000 shall become available October 1, 2020; (D) $1,925,000,000 shall become available October 1, 2021