Fi
Fi Series 3+
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Best Dog GPS Trackers · head-to-head
Fi Series 3+ vs Garmin Alpha TT25
A sourced, side-by-side comparison. Fi Series 3+ is cheaper at —. Every spec and price links to its source.
Garmin
Garmin Alpha TT25
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Full spec sheet
✓ marks the stronger figure where "more" — or "less", for price and weight — is unambiguously better.
| Spec |  Fi Series 3+ |  Garmin Alpha TT25 |
|---|---|---|
| US price | — | — |
| Brand | Fi | Garmin |
| Released | — | — |
| Connectivity type | lte-cellular | radio-uhf |
| Positioning system | gps | — |
| Subscription required | Yes | No |
| Monthly fee (USD) | — | 0 |
| Battery life days | — | — |
| Live update interval (s) | — | — |
| Weight grams | — | — |
| Waterproof rating | IP68 | — |
| Range miles | — | — |
| Activity tracking | Yes | No |
| Health monitoring | Yes | No |
| Containment fence | No | No |
Sources — Fi Series 3+: fitracking.com (verified 2026-07-13). Garmin Alpha TT25: garmin.com (verified 2026-07-13).
What's the difference between the Fi Series 3+ and Garmin Alpha TT25?
Where the two actually differ on the specs we track (4 of 12). Matching specs are omitted.
- Connectivity type: Fi Series 3+ lte-cellular vs Garmin Alpha TT25 radio-uhf
- Subscription required: Fi Series 3+ true vs Garmin Alpha TT25 false
- Activity tracking: Fi Series 3+ true vs Garmin Alpha TT25 false
- Health monitoring: Fi Series 3+ true vs Garmin Alpha TT25 false