2 layers25.4 × 17.8 mm

Texas Instruments
The ISO154X is an uncategorised made by Texas Instruments with 8 pins.
PCBKit's library has its KiCad symbol (Celestial_Digital_Isolator:TI ISO154x, from Altium's library), ready for a KiCad board. 1 open-source board in 1 repository on GitHub use it.
The library has no footprint for this part yet.
| Pin | Name | Type |
|---|---|---|
| 1 | VCC1 | Passive |
| 2 | SDA1 | Passive |
| 3 | SCL1 | Passive |
| 4 | GND1 | Passive |
| 5 | GND2 | Passive |
| 6 | SCL2 | Passive |
| 7 | SDA2 | Passive |
| 8 | VCC2 | Passive |

Yes. The symbol is Celestial_Digital_Isolator:TI ISO154x, both drawn on this page. PCBKit places them on a board for you when you design with it.
1 board in 1 repository on GitHub; the most starred are listed on this page, with their KiCad files.