[The nut that holds it in place is missing.] R&T Toilet Fill Valve A1320 Replacement Kit

Fix slow filling, noisy, leaking, or running toilets with this plumber-approved kit. Crafted from BPA-free ABS plastic, it features an anti-siphon design to prevent water contamination and save water. The quick-locking nut ensures easy installation without tools, and the adjustable height (9.2"-13") fits most American Standard and common toilet tanks. Serving the U.S. since 2002, R&T offers reliable toilet repair solutions with dedicated customer support.