How to achieve the best projection effect

40-41 is suitable (39-40 is worn)

Size: 130X75X37mm

brain waves

Tyre Inflation Gun, Digital Display, Tire Pressure Gauge Color:Black How to achieve the bestProduct information: Material: Copper body Display mode: LCD high definition digital display Pressure unit: four units can be switched to PSI, KPa, Bar, Kgf cm^2 Measurement range: 4 kinds of measurement units are supported, the maximum range is 200 (psi) =13. 79 (bar) = 14. 06 (kgf cm2)=1378. 95kPa Working temperature: 10 to 50C Key functions: switch key (left), unit switch key (right) Working voltage: DC3. 1V (use a pair of 1. 5V AAA batteries)