Núm vòi nước vườn nhỏ có thể tháo rời cho chốt vuông 6mm

If the landlord decided that you should not everybody should use the garden faucet, here a solution: This small removable garden faucet knob for 6mm square pin works suprisingly well, even if “only” printed with PLA (but you have to press it inside before turning).

The advantages: It is so small that it is nearly invisible if hidden in the bushes (if printed in the right colors, obviously).