← Gear database

Casio Pro Trek PRG-340 vs Coros APEX 4 (42mm)

Weight and specs compared for 2026 — and which one to choose.

Coros APEX 4 (42mm) is the lighter option — 10 g lighter than the Casio Pro Trek PRG-340 (15% less weight). If grams matter to you, that is the one to beat.
shopping_cart Check today's price on Amazon
Spec Casio Pro Trek PRG-340 Coros APEX 4 (42mm)
Weight 66 g · 0.066 kg · 0.15 lb 56 g · 0.056 kg · 0.12 lb
Brand Casio Coros
Category Electronics Electronics
Casio Pro Trek PRG-340
66 g

Solar-powered outdoor watch with triple sensor.

Full details →
Coros APEX 4 (42mm)
56 g

Mountain sports GPS watch with dual-frequency satellite positioning for improved accuracy, ECG heart rhythm monitoring, and barometric altimeter for navigation

Full details →

HikeLoad is reader-supported. As an Amazon Associate we earn from qualifying purchases, at no extra cost to you. Learn more.

Casio Pro Trek PRG-340 vs Coros APEX 4 (42mm): which should you buy?

If saving weight is your priority, the Coros APEX 4 (42mm) wins — at 56 g it is 10 g (15%) lighter than the Casio Pro Trek PRG-340 (66 g). That said, the heavier option may justify the extra grams with more capacity, durability or comfort, so weigh the trade-off against how you'll use it.

See where both rank against everything else in this category on the lightest electronics page, or browse the full gear weight database.

More electronics comparisons

Casio Pro Trek PRG-340 vs Garmin Instinct 3 Solar 45mm Casio Pro Trek PRG-340 vs Coros Apex 4 (42mm with silicone strap) Casio Pro Trek PRG-340 vs Garmin Xero C1 Pro Chronograph Casio Pro Trek PRG-340 vs Polar Grit X Casio Pro Trek PRG-340 vs Garmin Epix Gen 2 Sapphire Smartwatch Casio Pro Trek PRG-340 vs Garmin Epix Pro Gen 2 Sapphire 47mm