Frisco Sensors mini electric portable air compressor, multi function cordless air inflator is perfect for bicycle tires and small tires, small swimming rings, basketball, football, rugby but do not support big truck tires, big motorcycle tires, travel pillow, inflatable toys, big pool inflatable devices like pool floats, etc. The air pump contains only 30 to 60% of the electricity, so you need to fully charge it before using it for the first time. Due to the operating principle of the air pump, all pumps on the market are very noisy. Tested at a distance of one meter to the product, most products on the market have a resolution of 90 decibels and our air pump is optimized for a noise reduction of 80 decibels. If you use it, you can still feel a bit loud, but it's normal, feel free to use it. This product is a portable mini air pump that can be used as emergency equipment for car tires and is not a professional tire pump for car tires. Frisco Sensors air pump can not be used in trucks, air mattresses. The Product Has 4 Modes. The default PSI of Car mode is 35PSI/2.4bar, and the adjustable range of PSI is 0-65PSI. The default PSI of Motorcycle mode is 40PSI, and the adjustable range of PSI is 0-55PSI. The default PSI of Bicycle mode is 38PSI, and the adjustable range of PSI is 0-150PSI. The default PSI of Ball mode is 8PSI, and the adjustable range of PSI is 0-15PSI. Each mode has set the maximum safety PSI to prevent the tires from bursting. Make Reading Accurate after turning on the device, if the measured pressure value is not 0, press the U/LED [16] and the SET [19] button for 3 seconds at the same time, the device will enter the automatic reading clearing process, and the display will flash rapidly. Note: The product has been cleared from the factory. Due to altitude differences, clearing readings will increase the measurement accuracy. Do not connect the inflated items when clearing. How To Use: Long press the power button for 3 seconds and wait for the progress bar to complete. Short press the set button to select 4 modes of inflatable special scene. Short press the U/LED button to switch the air pressure unit,1PS1=6.89KPA,1BAR=100KPA,1Kg/cm2=98KPA Short press the preset +/.buttons to adjust the preset pressure. Long press them to adjust the value quickly. Short press the power button to start.