If things go off the rails while you're scuba diving, you want to have gear you can trust in an emergency. ScubaLab highlights the latest secondary regulators so you can pick the right octo for you. You can find more scuba gear and ScubaLab reviews on our gear page.

Apeks MTX-R Octo

Based on the rugged MTX military scuba diving regulator, the new MTX-R from Apeks is designed for heavy-duty use in extreme conditions, so it makes sense to have an octo just as capable. The working parts of the MTX-R octo are identical to the primary — down to the heat-exchange fins and metal diaphragm cover that’s stamped: “Extreme Cold Water Use.” What’s different is the yellow purge and highlights, and a longer yellow braided hose. Like the primary regulator, the octo can be configured with left- or right-side hose and has a quick-change exhaust port; it comes fitted with the short version to keep it compact.

Cressi Compact Pro Octo

With smooth breathing performance in a second stage regulator that weighs less than 5 ounces, the Cressi Compact Pro has become a favorite for travelers or anyone who wants a reg you can dive all day without experiencing jaw fatigue. The Compact Pro Octo combines those same qualities with a bright-yellow purge cover and hose. Like the primary, the octo has a top-mounted dive/ predive switch that’s plainly marked and easy to see so you can confirm at a glance it’s ready for that giant stride.

Oceanic Alpha 10

Delivering the same dependable and easy-breathing performance of the new Alpha 10 line of regs, this octo also shares the large, easy-grasp dive/predive control mounted on the side of the reg body. Weighing just 6 ounces with a small, rounded profile, the octo tucks out of the way easily while its neon-yellow purge and braided hose make it stand out boldly no matter where it’s mounted on your BC.