The Quick Verdict
These two land within a penny of each other, which makes this a straight feature fight. Get the Garmin Approach Z10. Its Bluetooth connectivity opens up features the Blue Tees simply doesn't have — Range Relay and Find My Garmin — and Garmin publishes the weight and dimensions Blue Tees doesn't. The Blue Tees Series 4 Ultra is worth it only if you strongly prefer an OLED readout and don't care about the Garmin ecosystem. Check price at PlayBetter →
What They Have in Common
Both rangefinders are $300, offer 6x magnification, ±1 yard accuracy, and slope modes with a tournament-legal switch. Both lock onto flags and confirm with vibration. Both run on CR2 batteries — no charging required, which is genuinely convenient since CR2s are easy to find mid-trip if something goes wrong. Water ratings are the same splash level (the 4 in IP54 and IPX4); the Blue Tees also carries a dust rating, which the Z10 doesn't.
Where They Differ
Display Technology
The Blue Tees uses an OLED display with brightness control, and I'd guess the ability to dial brightness is useful in variable light. The Garmin uses a transparent PDLC display with black readouts. I don't have hands-on time with either, and which you prefer is genuinely subjective.
Connectivity and Ecosystem
The Z10 has Bluetooth and a Find My Garmin function. Range Relay is worth flagging: it sends your ranged distance to a compatible Garmin watch, handheld or the Garmin Golf app, which is useful if you're tracking data. Find My Garmin is exactly what it sounds like — useful the one time you leave your rangefinder on a cart and it drives away. The Blue Tees has no app connectivity or Bluetooth. If you're deep in the Garmin world, the Z10 fits. If you're not, it's still a feature the Blue Tees doesn't have at all.
Battery Life
Both use CR2 batteries, but the Garmin claims up to a year on a single CR2. The Blue Tees takes three CR2s, and Blue Tees doesn't publish how long a set lasts, so I can't tell you which goes longer between swaps. What I can tell you is the spare: one battery in your bag for the Z10, three for the Blue Tees.
Build and Magnet
Garmin publishes dimensions (4.1 × 3.1 × 1.7 in, 6.3 oz) and includes a cart magnet. Blue Tees has their Ultra Magstrip for mounting but doesn't publish weight or dimensions — which is a minor annoyance if you want to know what you're buying before it arrives. Both have some form of magnetic mounting, so neither has an edge there in terms of cart-mounting convenience.
Who Should Buy Which
Get the Blue Tees Series 4 Ultra if:
- You've used OLED rangefinders before and know you prefer an OLED readout
- You want adjustable brightness and find yourself playing in conditions where you'd actually use it — early morning rounds, late afternoon sun at low angles
- You're not in the Garmin ecosystem and have no interest in Bluetooth connectivity on a rangefinder
- You find a discount that pushes the Blue Tees below the Z10's price; at identical MSRP, the Z10 wins, but even $20 less changes the math a bit
Get the Garmin Approach Z10 if:
- You want to try a transparent PDLC display with black readouts instead of an OLED
- You're the golfer who regularly leaves gear on carts; Find My Garmin is there for exactly that
- You use a Garmin watch, handheld or the Garmin Golf app and want Range Relay to feed ranged distances through to it
- You want one battery to keep track of — a single CR2 rated up to a year
The Bottom Line
At $299.99 vs $299.98, you're picking purely on features. The Garmin Approach Z10 brings Bluetooth with Range Relay, Find My Garmin, a single CR2 rated up to a year, and published weight and dimensions that tell you what you're actually buying. The Blue Tees Series 4 Ultra isn't a bad rangefinder — the OLED with brightness control is a legitimate preference for some golfers — but at equal price, it gives you less. The Z10 is the stronger buy at this price point.