150 PSI Portable Pocket Bike Pump Electric Air Pump Rechargeable Compressor Tire Inflator For Bicycle Tire with Digital Gauge

Before use, please note if there is already gas in the inner tube.

There are 2 cases as follows：

1. Inflating a hollow inner tube: first connect the pump to the inner tube valve and then start the pump to inflate the inner tube.

2. Replenishment of an inner tube that already contains air: start the pump first, switch on the inflation mode, and finally connect the pump to the inner tube valve to inflate it.