You know you’ve found the perfect reg when you barely notice it’s there. Our 2018 scuba diving Gear Guide breaks down the key features and pricing for some of the best scuba diving regulators models on dive shelves so you can find the right reg.

The new XL4 is a super-compact reg geared to high performance in challenging conditions. Featuring a tough overmolded endcap, the first stage boasts an environmental diaphragm and large surface-area heat exchanger clamp to resist ice buildup. The lightweight second stage is designed to reduce jaw fatigue on long deco stops.

The latest version of this iconic reg is new inside and out, with a stylish soft diaphragm cover, a redesigned Venturi control and beefed-up performance. Not changed: The second stage is still light and compact for all-day comfort; the simple design keeps it reliable and easy to maintain; and the price remains as friendly as ever.

Aqua Lung's mighty-mite reg — with a cosmetic update for 2017 — is one of the most compact models on the market, making it a worthy travel companion. The first stage has a balanced diaphragm and features the new Auto Closure Device to keep water out. The balanced second stage offers user adjustment and the brand's venerable Comfo-Bite mouthpiece.

The T3 represents the pinnacle of Atomic Aquatics engineering delivered in ultralight titanium. This top-of-the-line reg, one of the lightest on the market, offers strong performance thanks to its exclusive Jet Seat high-flow first-stage piston in combination with the magnum lever enabled second stage. And it has a three year, 300-dive service interval warranty.

Beuchat's V First regulator is so compact and lightweight, it's a little like diving with no regulator at all. The piston first stage is ultra-small, and the tiny second stage uses a simple non-compensating downstream valve and a user adjustable Venturi control. Together they deliver solid breathing performance at an attractive price.

This reg offers the latest technology in a classic, timeless design. The first stage delivers consistent intermediate pressure regardless of tank pressure, and the pneumatically balanced second stage has a sleek, low-profile elliptical design for comfort and efficiency. A top-mounted Venturi switch and a metal breathing knob make precision adjustments a snap.

This unique regulator system — part of the Atelier line — comes with a balanced diaphragm first stage that is "T" shaped to both save space and allow for better hose arrangement. The T10 Cromo comes with the pneumatically balanced Galaxy second stage that offers a super simple elliptical design and comes with a cover plate made entirely of soft rubber.

Hollis' flagship reg is built for extreme conditions, with a tough industrial-plated PVD coating on every metal component of the first stage, including the pneumatically balanced brass valve. It's paired with the DCX second stage, which can be converted from right- to left-hose configuration without special tools and offers adjustable inhalation.

Tec divers will appreciate the 75XR-DR Full Tech Set, a new technical diving rig that includes a pair of 75XR first stages, a pair of compact DR nickel- and chrome-plated brass second stages with standard downstream valves, two hoses (24in/60cm to 7ft/210cm), one neck bungee strap and one dead bolt snap.

The Alpha 10 lets you choose a package that suits your dive style and budget. Available with either the cDX balanced diaphragm or sPX piston first stage, the Alpha 10 has a compact, pneumatically balanced second stage for responsive breathing performance, and a Venturi control to prevent air-wasting freeflows.

The Delta 5 has a new look, but that's not what helped it win ScubaLab's Testers Choice in the under $600 category. It was a combination of performance and value, including the ability to dial in preferred resistance with Oceanic's Dynamic Adjustment Technology, all-metal pneumatic valve and ribbed heat exchangers on the first and second stages.

The MK11/C370 is a great choice for globe-trotting dive-trekkers. The balanced diaphragm MK11 is an ideal travel companion. The C370 brings forth the best features of its predecessor, the C350, while adding a balanced valve to its design. With the MK11/C370 reg in your bag you'll be ready to hit the road — and the water.

The new S620 TI second stage teams up with the proven MK25 EVO first stage to deliver smooth performance even in the most demanding conditions imaginable. The second stage is smaller and lighter than its predecessor, for improved diver comfort, but uses the same size diaphragm for quick response and effortless air flow.

With a breathing adjustment knob offering a wide range of resistance, divers can dial in their optimal rate. The balanced second stage also offers a Venturi control to limit free flow and a large purge cover with aggressive styling in brushed stainless steel. In addition, the lightweight first stage is compact, and ports are angled for streamlined hose routing.

Rebreathers represent the evolution of diving, and the Prism 2 is a full closed-circuit unit that can be controlled electronically or manually for divers who want to explore their limits or get closer to marine life. The rig comes standard with primary LED displays, plus an electronic secondary control and a complete backplate and wing assembly.