About this 3D model

- 3 batteries (this is the maker's mind) - Bluetooth amplifier XH-A158 (Manual volume adjustment is convenient to use) - 2 inch speaker - Charging module 134N3P (It seems to be convenient because it is used for both charging and discharging.) https://www.thingiverse.com/thing:1746166 -> power_bank_o_1.stl- I can't see it in the picture, but I used the XL6009 step-up module to send a stable 5V to the amplifier. - Circular switch KCD1-105 (It is 16 pi.) - Assembling round head screws (wrench heads are also required) 8 pieces of M4 * 8 ~ 10 / 8 pieces of M4 * 16 ~ 20 are required.