A three-point safety belt includes a belt body, a winder, a shoulder belt guide ring, and a lock tongue. The winder and the shoulder belt guide ring are fixed onto a vehicle body. The winder is located below the shoulder belt guide ring. The lock tongue is disposed on the belt body. The lock tongue divides the belt body into a shoulder belt and a waist belt. The shoulder belt penetrates through the shoulder belt guide ring. The free end, away from the lock tongue, of the shoulder belt and the free end, away from the lock tongue, of the waist belt are both wound in the winder. The winder synchronously winds or unwinds the shoulder belt and the waist belt.

A swimming pool cleaner coupled to a hose, wherein the hose is configured to automatically extend and retract

A speed reducer arrangement (200) for a line retraction device (100), including at least one lug (4) fixed on a surface of a rotatable hub (2) and configured to rotate along with the hub (2); at least one brake shoe (5) having at least one groove (8) extending therethrough and configured to at least partially receive the at least one lug (4), such that, as the hub (2) rotates, the at least one brake shoe (5) is configured to slidably move along the at least one groove (8) from an inactivated position, wherein the at least one brake shoe (5) is located nearest the center of the hub (2) to an activated position, wherein the at least one brake shoe (5) contacts at least one contact surface of the line retraction device (100) to thereby slow the rotation of the hub (2); and at least one biasing member (6) configured to urge the at at least one brake shoe (5) towards the inactivated position.