Rust-proof aluminum shell Built in hardened steel roller, connevient the ball moving Maximum temperature: 100 °C = 220 °F Noise level range: 75--95dBA Nylon end caps at both ends of the shell means for positioning the ball while preventing the entry of dust and water, and therefore allows it to operate in dusty and wet environments. Inlet and outlet are standard pipe thread, so that the exhaust pipe can be drawn to ensure barrier-free exhaust. For meeting different installation location, K series pneumatic ball vibrator has four mounting holes: two horizontal and two vertical