HYKE THU224 Dual-Flush Toilet Flushing Unit with Nut for Two-Piece Aquia (Model #ST412M)

Overview: Replacement dual-flush unit designed for two-piece Aquia toilets. This HYKE THU224 assembly includes the nut and delivers both full and half flush options to save water, restore flushing performance, and extend the flush mechanism’s service life. Compatibility: Made for Two Piece Aquia New/Old Style, Aquia III, and Aquia II toilets. Compatible two-piece model numbers include #CST414M, #ST413M, #ST416M, and #ST464M. Note: this unit is intended for split-type (two-piece) toilets only and is not suitable for one-piece toilet designs. Dimensions & Requirements: Minimum tank water height must exceed 11.81 inches for proper operation. Total dual flush height is 12 3/8 inches. Construction & Seals: The dual-flush unit is constructed from durable material and fitted with rubber gaskets for reinforced durability and reliable sealing. Installation Notes: This flush mount is THU224. For THU224 installations, you generally do not need to remove the tank—replace the upper section only. For other flush assemblies (e.g., THU435), remove the existing button/upper component and install the new button. Fit Advisory: The THU224 may fit some non-Aquia toilets, but always measure the tank height and drain opening before purchasing. Incorrect sizing can cause installation issues or reduced flushing performance. We prioritize customer satisfaction through verified compatibility and clear fit guidance.