What They Have in Common
Both have slope with a legal-play switch, so you can toggle it off for competition rounds. Both use pulse vibration to confirm flag lock. Both are water-resistant enough for a normal rainy round. At $299 each, they're sitting in the same price bracket but targeting different golfers — the overlap is thinner than you'd expect at the same price point.
Where They Differ
Display and Optics
This is where the Series 4 Ultra pulls clear. It runs an OLED display with adjustable brightness, which is a meaningful advantage over standard LCD setups. OLED gives you deeper contrast and better low-light readability — useful for those early morning tee times when the sun hasn't fully come up yet. Blue Tees also publishes a 6x magnification spec and a ±1 yard accuracy claim, which gives you something concrete to hold them to.
The CSi Pro doesn't publish its magnification or display type, which is a little frustrating at $299. Callaway does note multi-coated optics, which should help with glare and clarity, but without a magnification number or accuracy spec in the data, there's nothing to compare directly. Seems like Callaway is betting that the club selection feature carries the buying decision, so they're not leading with optics.
What the CSi Pro Does That the Series 4 Ultra Doesn't
The CSi Pro's headline feature is club selection — it doesn't just tell you 157 yards, it suggests which club to hit. Callaway calls it CSi. How useful this actually is depends entirely on how good the underlying algorithm is and whether it's been calibrated to your bag, but the concept is real. If you're a higher handicap golfer who sometimes stares at a yardage and still isn't sure what to pull, this could be genuinely helpful. For a single-digit player who already knows their numbers cold, it's probably background noise.
The CSi Pro also has a scan mode, which lets you sweep across the fairway and pick up continuous yardages to multiple targets. The Series 4 Ultra doesn't list this feature.
Battery and Range
The Series 4 Ultra runs on three CR2 batteries — not rechargeable. CR2s are at every pharmacy, which matters on a golf trip when you're not near a charging cable. The downside is you'll replace them eventually. Blue Tees also claims a 1,200-yard range with flag lock out to 350 yards, which is solid.
The CSi Pro tops out at 1,000 yards. Callaway doesn't publish battery type or life, so it's hard to know what you're working with there. At 5.6 oz, it's a known quantity in your hand — Blue Tees doesn't publish a weight for the Series 4 Ultra.
Build and Warranty
The Series 4 Ultra is IP54 rated, which is a real spec — it'll handle rain and dust without issue. The CSi Pro is listed as "water-resistant" without a formal rating, which could mean the same thing or could mean less. Callaway does back the CSi Pro with a two-year warranty, which is worth something. Blue Tees doesn't list a warranty in the input data.
Who Should Buy Which
Get the Blue Tees Series 4 Ultra if:
- You prioritize optics and display — the OLED with brightness control is the best display feature at this price point
- You play early mornings or late afternoons and need a display that actually works in low light
- You're the 12-handicap who already knows your yardages by feel and just wants fast, accurate distance readings
- You want a concrete accuracy spec (±1 yard) and a longer range ceiling (1,200 yards)
Get the Callaway CSi Pro if:
- You're the 18-handicap who hits 162 yards and genuinely waffles between an 8-iron and a 7 — the club suggestion is there for exactly that moment
- You want scan mode to sweep across a fairway and check multiple yardages before committing
- Brand trust matters to you and you feel better with Callaway's name and two-year warranty behind the device
- You want a known weight (5.6 oz) and a compact build
The Bottom Line
Same price, genuinely different products. The Series 4 Ultra wins on display quality and published specs — the OLED, the magnification, the accuracy number. The CSi Pro wins if the club selection feature actually fits how you think on the course. For most golfers who already know their clubs and just want reliable yardages with a great display, the Series 4 Ultra gives you more to work with. The Callaway's club selection is interesting, but I'd want to know more about how it's calibrated before betting $299 on it being useful to me specifically.
Get the Blue Tees Series 4 Ultra.