A attachment system is formed by a primary device and a secondary device connected to the primary device in a pivoting manner. The primary device has a main body, two lateral sides and a bar for attaching the primary device to another object. Each of the lateral sides has a protrusion extending laterally outward from the lateral sides. The secondary device has two lateral sides, each equipped with an aperture that corresponds to one of the protrusions on the primary device, so that fitting the protrusions into the apertures pivotally connects the primary device to the secondary device, with the lateral sides of the secondary device being disposed outside of the lateral sides of the primary device. The secondary device can be pivoted between a folded position where the secondary device lies against the primary device, and an open position where the secondary device is raised up.

A two-tone whistle that alters an audible patch that reduces confusion when multiple athletic events are played with whistles being blown during the multiple athletic events. The two-tone whistle includes a mouthpiece, a resonate chamber, a ball, a lever and a lanyard aperture. The slotted edge is integral to the lever and is adapted to move up or down as the lever moves up or down producing a first audible pitch and a second audible pitch, wherein the first audible pitch is lower than the second audible pitch.

A two-tone whistle that alters an audible patch that reduces confusion when multiple athletic events are played with whistles being blown during the multiple athletic events. The two-tone whistle includes a mouthpiece, a resonate chamber, a ball, a lever and a lanyard aperture. The slotted edge is integral to the lever and is adapted to move up or down as the lever moves up or down producing a first audible pitch and a second audible pitch, wherein the first audible pitch is lower than the second audible pitch.

The present disclosure provides a hose for transporting used fracturing liquid and manufacturing method thereof. The hose may include an outer layer, an enhancement layer and an inner layer. The outer layer may include a first polymer. The enhancement layer may include a synthetic fiber. The inner layer may include a second polymer. The surface of the outer layer may include an alerting object. The alerting object may include at least one of a luminous layer, a light band, a reflective layer, an identification layer or a sound generating object. The luminous layer may include at least one of a strip-shaped luminous layer, a ring-shaped luminous layer or a spiral-shaped luminous layer, arranged on the outer surface of the outer layer.

The present disclosure provides a hose for transporting used fracturing liquid and manufacturing method thereof. The hose may include an outer layer, an enhancement layer and an inner layer. The outer layer may include a first polymer. The enhancement layer may include a synthetic fiber. The inner layer may include a second polymer. The surface of the outer layer may include an alerting object. The alerting object may include at least one of a luminous layer, a light band, a reflective layer, an identification layer or a sound generating object. The luminous layer may include at least one of a strip-shaped luminous layer, a ring-shaped luminous layer or a spiral-shaped luminous layer, arranged on the outer surface of the outer layer.

Example clippable multi-tone whistles, as well as systems and methods for manufacturing the same are described. An example clippable multi-tone whistle may comprise: a clip attached to a whistle body. The whistle body comprises a flat surface under the clip; a first opening configured to allow air flow to come into the whistle body; and on the flat surface a second opening configured to allow air flow to come out of the whistle body. The second opening is at least partially blocked by the clip, which controls direction of one or more air flows coming out of the second opening. The whistle part is configured to generate a plurality of different sound tones in accordance with user finger movements around the clip and the second opening. The whistle may further comprise a glass breaker, a length scale, and a bolt action switch, which may function as a fire starter.

Example clippable multi-tone whistles, as well as systems and methods for manufacturing the same are described. An example clippable multi-tone whistle may comprise: a clip attached to a whistle body. The whistle body comprises a flat surface under the clip; a first opening configured to allow air flow to come into the whistle body; and on the flat surface a second opening configured to allow air flow to come out of the whistle body. The second opening is at least partially blocked by the clip, which controls direction of one or more air flows coming out of the second opening. The whistle part is configured to generate a plurality of different sound tones in accordance with user finger movements around the clip and the second opening. The whistle may further comprise a glass breaker, a length scale, and a bolt action switch, which may function as a fire starter.

There is provided a horn device for a railcar capable of delivering horn sound to a long distance in a traveling direction and being less likely to spread sound in a car width direction. A horn device for a railcar according to one aspect of the present invention includes: a whistle portion that is supplied with compressed air to make horn sound in a traveling direction; a duct located in the traveling direction of the whistle portion and having an opening portion at an end portion in the traveling direction; and at least one partition plate that is disposed perpendicularly to a car width direction, extends in a car longitudinal direction, and divides the interior of the duct.

A set of two or more whistles. Each whistle of the set sounds differently from each other based on a different type of sound or a different value of a characteristic of sound common to whistles of the set. Sound characteristics may include but not limited to pitch, quality, loudness, and/or duration. Each whistle in the set may be different in appearance from each other in the set. Appearance characteristics may include but not limited to color, numbering, design, light up features, size, and/or shape. Alternatively; the whistles in a set may have a common appearance characteristic, but each whistle may have its own value of the common appearance characteristic. Additional element(s) such as lanyards or mouthpieces may be added to whistles of a set to distinguish them from each other. The set of whistles may be included in a kit having a box for removably storing the whistles.

A set of two or more whistles. Each whistle of the set sounds differently from each other based on a different type of sound or a different value of a characteristic of sound common to whistles of the set. Sound characteristics may include but not limited to pitch, quality, loudness, and/or duration. Each whistle in the set may be different in appearance from each other in the set. Appearance characteristics may include but not limited to color, numbering, design, light up features, size, and/or shape. Alternatively; the whistles in a set may have a common appearance characteristic, but each whistle may have its own value of the common appearance characteristic. Additional element(s) such as lanyards or mouthpieces may be added to whistles of a set to distinguish them from each other. The set of whistles may be included in a kit having a box for removably storing the whistles.