Zeus Arc

The key difference between the Arc and every later GT model is the vapour path. On the Arc, the heating chamber and vapour path are made of stainless steel. The Arc GT introduced GoldSink technology, which gold-plates those same parts.

Stainless steel is a proven chamber material: heat resistant, neutral enough in everyday use and easy to clean. If you chase the last bit of flavour purity in a side-by-side test, a GT model is the better pick.

The Arc runs three presets, typically 205 °C, 215 °C and 225 °C. There is no free temperature dial on the device. The values can be changed through the firmware, which needs a computer and the manufacturer software.

For beginners that is more help than limit: the three steps cover the usual range without any need to think in degrees. Anyone who wants finer control is better served by a device with a free temperature setting.

Heating works by conduction — the chamber walls warm the material directly. That heats up quickly and is efficient in a compact device, but it rewards an even fill; otherwise the edges extract faster than the middle.

The anodised aluminium body is built for pocket carry. A multi-tool for filling and stirring is built into the device, and a haptic pulse signals that the target temperature has been reached.

The Arc is discontinued. Screens and mouthpieces are still around because Zeus shares many parts across the Arc line, but there is no replacement for the built-in battery — once it is worn, the device's life ends.

Buying makes sense mainly when leftover stock sits well below the price of the current models. Otherwise the Arc GT3 gives you the gold-plated chamber and newer electronics for a little more.