Abstract: A di(2-ethylhexyl) terephthalate composition is provided. The di(2-ethylhexyl) terephthalate composition comprises di(2-ethylhexyl)terephthalate, at least one of a first component, a second component and a third component, and a fourth component When the di(2-ethylhexyl) terephthalate composition is characterized by gas chromatography (GC), the first component is eluted at a retention time ranging from 4.8 minutes to 6.0 minutes, the second component is eluted at a retention time ranging from 9.0 minutes to 10.0 minutes, the third component is eluted at a retention time ranging from 10.1 minutes to 12.0 minutes, and the fourth component is eluted at a retention time ranging from 21.0 minutes to 22.1 minutes. The ratio of the total area of the chromatographic peaks indicating the first component, second component, and third component to the area of the chromatographic peaks indicating the fourth component is 0.135 to 1.720.

Abstract: A di(2-ethylhexyl) terephthalate composition is provided. The di(2-ethylhexyl) terephthalate composition comprises di(2-ethylhexyl)terephthalate, at least one of a first component, a second component and a third component, and a fourth component When the di(2-ethylhexyl) terephthalate composition is characterized by gas chromatography (GC), the first component is eluted at a retention time ranging from 4.8 minutes to 6.0 minutes, the second component is eluted at a retention time ranging from 9.0 minutes to 10.0 minutes, the third component is eluted at a retention time ranging from 10.1 minutes to 12.0 minutes, and the fourth component is eluted at a retention time ranging from 21.0 minutes to 22.1 minutes. The ratio of the total area of the chromatographic peaks indicating the first component, second component, and third component to the area of the chromatographic peaks indicating the fourth component is 0.135 to 1.720.

Abstract: An acoustic system includes a conduit, a microphone coupled to an end of the conduit, and a rigid moisture resistant barrier coupled to another end of the conduit to prevent moisture from traversing the length of the conduit towards the receiver. The moisture resistant barrier dampens an audio signal traversing the conduit. The moisture resistant barrier has a submersion rating at least equal to a 7 Ingress Protection rating.

Abstract: An acoustic system includes a conduit, a microphone coupled to an end of the conduit, and a rigid moisture resistant barrier coupled to another end of the conduit to prevent moisture from traversing the length of the conduit towards the receiver. The moisture resistant barrier dampens an audio signal traversing the conduit. The moisture resistant barrier has a submersion rating at least equal to a 7 Ingress Protection rating.

Abstract: An acoustic system includes a receiver (or microphone), a tube, or a moisture resistant screen. The receiver is capable of outputting an audio signal, while the microphone receives an audio signal. The tube is in connection with the receiver (or microphone) and the audio signal travels along a length of the tube. The moisture resistant screen is fitted at an end of the tube. The moisture resistant screen prevents moisture from passing along the tube toward the receiver, and causes an amount of damping to the audio signal. The moisture resistant screen is configured to have a submersion rating greater than or equal to 7 IP.

Abstract: An acoustic system includes a receiver (or microphone), a tube, or a moisture resistant screen. The receiver is capable of outputting an audio signal, while the microphone receives an audio signal. The tube is in connection with the receiver (or microphone) and the audio signal travels along a length of the tube. The moisture resistant screen is fitted at an end of the tube. The moisture resistant screen prevents moisture from passing along the tube toward the receiver, and causes an amount of damping to the audio signal. The moisture resistant screen is configured to have a submersion rating greater than or equal to 7 IP.

Abstract: An acoustic system includes a receiver or microphone, a tube, a barrier, and an equalization device. The receiver is capable of outputting an audio signal. The tube is in connection with the receiver and the audio signal travels along a length of the tube. The barrier is fitted along the tube and the barrier prevents moisture from passing along the tube toward the receiver. The barrier causes an amount of damping to the audio signal. The equalization device is in connection with the receiver and the equalization device counteracts the damping by the barrier. The barrier is configured to have a submersion rating greater than or equal to 7 IP.

Abstract: An acoustic system includes a receiver or microphone, a tube, a barrier, and an equalization device. The receiver is capable of outputting an audio signal. The tube is in connection with the receiver and the audio signal travels along a length of the tube. The barrier is fitted along the tube and the barrier prevents moisture from passing along the tube toward the receiver. The barrier causes an amount of damping to the audio signal. The equalization device is in connection with the receiver and the equalization device counteracts the damping by the barrier. The barrier is configured to have a submersion rating greater than or equal to 7 IP.

Abstract: A walk assistance device includes a handle and a base connected to a lower end of the handle. Two brake members extend from two ends of the base and two frames are pivotally connected to the base. Each of the frames has two wheels connected thereto, a gap is defined between each of the brake members and the wheels. A spring is connected between each of the frames and the brake members when pushing the handle toward the wheels which are pushed upward by the ground to contact the brake members.