Hello, I recently purchased a used ENGWE MBT26 bike but due to cold weather and roads, I only rode it in the driveway. it has a shift lever on the right to change gears. On the left side is a meter with a + and - Could someone tell me what this is used for? I am new to e-bikes and don't understand it. I thought it was to make the bike go faster But like I said I did not get to ride it that much Here is a picture of the meter. Also is this a pedal-assist bike? Thank you for any information you could give me