Organelle-specific potassium channel specifically responsible for potassium conductance in endosomes and lysosomes. Forms a potassium-permeable leak-like channel. Homodimer. Composed of two modules of six transmembranes, forming a homodimer with a tetrameric architecture. The six transmembrane regions of each module are tightly packed within each subunit without undergoing domain swapping. Forms a central ion-conduction pore lined by the side chains of the pore-lining helices. Conserved isoleucine residues (Ile-62 in the first module and Ile-288 in the second module) in the center of the pore serve as the gate in the closed conformation. In the widened channel in the open conformation, the same residues establish a constriction essential for potassium selectivity. Belongs to the TMEM175 family.