Hamilton Khaki Field AutovsTimefactors Speedbird PRS-51
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Measurements
Catalog photos are all shot at the same flattering size. These aren't: every case below shares one millimeter scale.

Khaki Field Auto

Speedbird PRS-51
Diameter
38mm
36mm
Lug-to-Lug
47mm
42mm
lowest
Thickness
11mm
lowest
11.4mm
Water Resistance
100m
100m
Power Reserve
80h
n/a
MSRP
$845
$436
lowest
Movement
Hamilton H-10
Miyota 9015
Case
4 specsCrystal & Dial
1 specsMovement
2 specsPricing
1 specsReviews
Synthesized for each watch independently from owner discussions, enthusiast forums, written reviews, and video reviewers.
Owners widely praise the Hamilton Khaki Field Auto for its classic military design, legibility, and versatile modern-vintage aesthetic that can be dressed up or down. Reviewers and owners alike commend its reliable H-10 automatic movement for accuracy, with one owner reporting deviations of less than one second per day, and its advertised 80-hour power reserve. The 38mm case is noted for its perfect proportions and comfortable wearability, though some find the bracelet's micro-adjustments limited and the lack of AR coating on the crystal can cause glare. On balance, owners and reviewers rate the Hamilton Khaki Field Auto highly for its value and solid build as an entry-level automatic watch.
The Hamilton Khaki Field Auto's smooth and precise bezel action is a standout feature. The watch's lume brightness is somewhat lacking, which might be a drawback for those who prefer a brighter glow in the dark. Reviewers disagree on the watch's size, with one reviewer finding the 38mm to be a pleasant surprise, while the watch is also available in 42mm.
Owners widely praise the Timefactors Speedbird PRS-51 for its value and classic pilot's watch aesthetic, noting its beautiful AR sapphire crystal and minimalistic dial. The 36mm case is described as wearing thinner than expected, though some find the 5-link bracelet stiff or heavy, while others praise its drape and articulation. Accuracy figures vary, with some reporting impeccable timekeeping and others noting deviations of +7 to +10 seconds per day from the Miyota 9015 movement. Overall, owners rate the Timefactors Speedbird PRS-51 highly for its attractive flieger design and excellent value at its price point.
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