The two Leetop systems differ in exactly these two areas you asked about — the ALP 606 is fanless (passive cooling) while the ALP 606-F uses an active fan, and the ALP 606-F is rated for a colder environment:
| Leetop ALP 606 | Leetop ALP 606-F | |
|---|---|---|
| Cooling | Fanless (passive) | Fan (active) |
| Minimum operating temperature | -20 °C | -25 °C |
| Maximum operating temperature | 75 °C | 75 °C |
In short, the "-F" variant trades silent, maintenance-free passive cooling for a fan-cooled design that extends the operating range down to -25 °C instead of -20 °C. The maximum operating temperature is the same at 75 °C for both.
If a fully fanless build matters more to you than the extra 5 °C of cold tolerance, the ALP 606 is the fit; if you need operation down to -25 °C, go with the ALP 606-F.
- ALP 606: https://leetopgroup.com/products/alp606
- ALP 606-F: https://leetopgroup.com/products/alp606f