Garmin Forerunner 165 Music vs Garmin Forerunner 405CX

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Forerunner 165 Music compared with Forerunner 405CX

	GarminForerunner 165 Music	GarminForerunner 405CX
Overview
Released
Released	February 2024	2009
Display
Case sizes
Case sizes	43 mm	47.75 mm
Panel
Panel	OLED	–
Always-on display
Always-on display	Yes	Yes
Display detail
Display detail	1.2-inch (30.4 mm diameter) colour AMOLED touchscreen, 390 x 390 pixels; optional always-on display; five physical buttons	Backlit monochrome screen, 27 mm diagonal and 124 × 95 pixels; touch-sensitive bezel and two buttons. Panel technology is unpublished in the maker's specification.
Screen protection
Screen protection	Chemically strengthened glass	–
Health and fitness
ECG
ECG	No	No
Blood oxygen
Blood oxygen	Yes	No
Skin temperature
Skin temperature	No	No
Sleep apnoea alerts
Sleep apnoea alerts	No	No
High blood pressure alerts
High blood pressure alerts	No	No
Body composition
Body composition	No	No
Fall detection
Fall detection	No	No
Crash detection
Crash detection	No	No
GPS
GPS	Single-band	Single-band
Water resistance
Water resistance	50 m	–
Sensors
Sensors	Garmin Elevate wrist heart rate; Pulse Ox; barometric altimeter; compass; accelerometer; thermometer; ambient light sensor; GPS, GLONASS and Galileo	High-sensitivity GPS receiver with HotFix; ANT+ heart-rate chest strap, optional foot pod and cycling speed/cadence sensor. No optical wrist sensor.
Health features
Health features	Continuous heart rate with high/low alerts; HRV status; Body Battery; stress, respiration and blood oxygen; advanced sleep and sleep score; sleep coach and nap detection; Health Snapshot; hydration and women's health tracking; no ECG app	–
Fitness features
Fitness features	Daily suggested running workouts and Garmin Coach plans; training effect and recovery time; wrist-based running dynamics and running power; PacePro; VO2 max and race predictions; pool and open-water swimming; running, cycling, strength, HIIT, yoga, Pilates, tennis, pickleball and padel profiles; point-to-point and breadcrumb course navigation, back-to-start and TracBack; no full offline maps or dedicated triathlon mode; no training readiness, load or status (Wareable and Tech Advisor)	Heart-rate-based calorie calculation developed with Firstbeat; custom and interval workouts, courses, Virtual Partner, Auto Lap, Auto Pause, Auto Scroll and configurable training screens.
Safety features
Safety features	Incident detection during selected activities, assistance and LiveTrack require a paired compatible smartphone and connectivity; live event sharing is Android-only	Up to 100 stored locations and navigation to a saved location; no base maps.
Battery and connections
Battery life (maker's claim)
Battery life (maker's claim)	Up to 11 days	Up to 8 hours
In low-power mode
In low-power mode	Up to 20 days	Up to 14 days
Mobile data option
Mobile data option	No	No
Works with
Works with	iPhone and Android	No phone pairing
Storage
Storage	4 GB	–
Battery life detail
Battery life detail	Smartwatch up to 11 days; battery saver smartwatch up to 20 days; GPS-only up to 19 hours; all-systems GNSS up to 17 hours; GPS-only with music up to 7 hours; all-systems with music up to 6.5 hours; actual life depends on display settings, enabled features and use	Rechargeable 300 mAh lithium-ion battery; up to eight hours with GPS or two weeks in power-save mode, according to the English owner's manual. Garmin Slovakia instead quotes nine GPS hours.
Charging
Charging	Garmin proprietary plug charging/data cable; rechargeable built-in battery	USB contact charging clip and AC adapter.
Connectivity
Connectivity	Bluetooth and ANT+ and Wi-Fi; stores music for Bluetooth headphones; Spotify, Deezer and Amazon Music downloads require compatible subscriptions; Garmin Pay; Connect IQ apps, watch faces and data fields; smart notifications; Android-only text responses and notification images; Garmin Share and Garmin Messenger; no cellular connection or multi-band GNSS	ANT+ computer transfers through a USB ANT stick; Garmin Connect and Garmin Training Center. No direct phone pairing.
Storage
Storage	4 GB memory/history; offline music playback	Up to 1,000 laps, 100 locations and approximately twenty hours of track points at one point every four seconds.
Design
Weight (lightest version)
Weight (lightest version)	39 g (better)	60 g
Software
Software	Garmin	Garmin
Case materials
Case materials	Fibre-reinforced polymer bezel; chemically strengthened glass; silicone band; 5 ATM water rating	IPX7 immersion protection, one metre for thirty minutes; the manual says the watch is not intended for swimming.
Size
Size	43 x 43 x 11.6 mm; Garmin lists 39 g without a separate body-only weight	47.75 × 70.5 × 16.4 mm and 60 g, according to the English manual; Garmin Slovakia rounds this to 48 × 71 × 16 mm. Width is used as the case size.
Bands
Bands	20 mm quick-release silicone bands; fits 126–203 mm wrists	Standard wrist strap and two additional form-fitting fabric straps for smaller or larger wrists.
Colours
Colours	Black/Slate Grey; Mist Grey/Whitestone; Turquoise/Aqua; Berry/Lilac (currently not sellable on the UK maker page)	Deep blue.
In the box
In the box	Forerunner 165 Music; charging/data cable; documentation	Watch, heart-rate chest strap, USB ANT stick, AC adapter, USB charging clip, additional wrist straps and documentation.