Rectangle

They offer high thermal performance thanks to their narrow design, which reduces air gaps and heat loss. They are lighter than rectangular ones due to the use of less material. Recommended for hiking, mountaineering, or extreme temperatures.

It plays an important role, depending on the intended use of the sleeping bag. Ideally, for hiking, trekking, or mountaineering, a sleeping bag weighing less than 1.5 kg is recommended to facilitate transport and reduce the load on the backpack.

On the other hand, sleeping bags with greater weight are preferred for camping or stationary use.

Left

It not only concerns the ability to connect with another sleeping bag but also the ease of use. The zipper on the left side (as you lie down) is more convenient for right-handed people.

Synthetic

The synthetic filling offers warmth even when the sleeping bag gets wet, while it is more economical and easier to care for. However, it is heavier and less compressible than down and has a shorter lifespan.