Kospet Tank M3 Ultra: specs, who it fits and compatible phones

Kospet Tank M3 Ultra is a sport watch released in 2024 that works with iPhone and Android. It lists Dual-band GNSS, 5ATM · IP69K and SpO2, Heart rate.

Specifications

Release year	2024
Case size	53 mm (approx.)
Display	AMOLED
Battery as listed	Up to 15 days
Water rating	5ATM · IP69K
GPS type	Dual-band GNSS
Operating system	KOSPET OS
Works with	iPhone and Android
Connection	No cellular connection
Plan needed	None
Health sensors	SpO2, Heart rate

Who it fits

Works with iPhone and Android.
Lists an exact water rating of 5ATM or higher.

Overview

The Tank M3 Ultra (~2024) is Kospet's big-screen rugged watch: a 1.96-inch AMOLED, dual-frequency GNSS (L1+L5), a military-grade build per Kospet and 5ATM + IP69K sealing, at a $149.99 official price (in stock at kospet.com, checked October 2026).

What it does well

A 1.96-inch AMOLED is among the largest screens on any watch in this catalog: big data fields, easy reading mid-workout.
Documented pool-swim tracking: Kospet's page lists SWOLF, average pace, stroke rate, lap count and heart-rate monitoring, with stroke recognition for freestyle, backstroke, breaststroke and butterfly.
Dual-frequency GNSS (L1+L5): the accurate positioning normally reserved for pricier sport watches.
5ATM + IP69K sealing, up to 15 days of listed battery, Bluetooth calling and 170+ sport modes.

Tradeoffs to know

At roughly 53 mm (approximate in our data) this is a very large watch; smaller wrists should look elsewhere in the Tank line.
No NFC payments and no third-party apps (KOSPET OS).
No offline maps are mentioned on the manufacturer page.
The 5ATM + IP69K ratings cover exposure and pool swimming; no dive rating appears on the manufacturer page.

Price and availability

$149.99 official price, in stock at kospet.com (checked October 2026); a European retailer lists it from EUR 72: different markets and sellers, not the same price. Prices can change.

FAQ

Is the Tank M3 Ultra good for hiking?

The dual-frequency GNSS, 15-day listed battery and military-grade build suit it to long outdoor days. Note that the manufacturer page mentions no offline maps, so plan around recorded tracks rather than on-wrist mapping.

Can it record pool swims?

Yes: Kospet documents SWOLF score, average pace, stroke rate, lap count and heart rate, with stroke recognition across the four main strokes.

Who is the 1.96-inch screen for?

Anyone who wants maximum readability: big data fields at a glance. The tradeoff is a roughly 53 mm case that wears large.

How it compares

Closest models from Kospet

Model	Release year	Case size	Battery as listed	Water rating	GPS type	Works with
Kospet Tank T3 Ultra 2	2024	51 mm (approx.)	470mAh · 12 days · 30-35 GPS hours (approx.)	5ATM · IP69K	Dual-band GNSS	iOS and Android
Kospet Tank M4	2025	52 mm (approx.)	Up to 15 days regular use	10ATM · IP69K	Dual-band GNSS	iOS and Android
Kospet Tank T4	2025	50 mm (approx.)	Up to 15 days (approx.)	10ATM (approx.)	Dual-band GNSS	iOS and Android

Closest models from other brands

Model	Release year	Case size	Battery as listed	Water rating	GPS type	Works with
Amazfit T-Rex 3	2024	48.5 mm	Up to 27 days in regular mode · up to 40 days in saver mode	10ATM	Dual-band GNSS + maps	iOS and Android
COROS PACE Pro	2024	46 mm	Up to 20 days · 38 GPS hours	5ATM	Dual-band GNSS + maps	iOS and Android
COROS Vertix 2S	2024	50.3 mm	40 days · 118 GPS hours (approx.)	10ATM	Dual-band GNSS + maps	iOS and Android

Compared with Kospet Tank M4, Kospet Tank M3 Ultra lists an older release year (2024 against 2025).

Compared with Kospet Tank T4, Kospet Tank M3 Ultra lists an older release year (2024 against 2025).

Only values listed exactly are compared.

Phone compatibility and plan

No plan is listed as needed.

Sensors and features are listed as the maker names them and are not medical measurements.

Related guides and lists

Last verified September 26, 2026

Features change with updates. Check the maker's current details. See our methodology