Potassium channel; forms a potassium-permeable leak-like channel with weak selectivity for potassium (PubMed:32267231). The channel is permeable for K(+), Rb(+) and Cs(+) (PubMed:32267231). Homotetramer. The six transmembrane regions are tightly packed within each subunit without undergoing domain swapping (PubMed:32267231). Transmembranes TM1-TM3 are positioned on the inner circle of the channel tetramer and participate in inter-subunit interactions that are central to the assembly of the ion conduction pore (PubMed:32267231). The RxxxFSD motif within transmembrane TM1 coordinates a network of specific inter- and intra-subunit interactions with other conserved residues on TM2 and TM3 and plays a key role in the tetrameric assembly of the channel (PubMed:32267231). Transmembrane TM4-TM6 are positioned on the periphery of the channel and do not contribute to contacts with neighboring subunits (By similarity). Transmembrane TM1 forms the pore-lining inner helix at the center of the channel, creating an hourglass-shaped ion permeation pathway in the channel tetramer (By similarity). Hydrophobic residues (Leu-35, Leu-39 and Leu-42) on the C-terminal half of the TM1 helix form a bottleneck along the ion conduction pathway and serve as the selectivity filter of the channel (PubMed:32267231). Thr-38 is required for potassium ion selectivity (PubMed:32267231). Belongs to the TMEM175 family.