The Tundra is 1 of fi’zi:k’s 3 Spine Concept™ MTB Saddle shapes. Of these 3, the Tundra shape is flat, narrow and long.

Tundra M5 is for The Snake: Flexible Spine

If you are very spinally flexible (far less than 90 degrees between your straight legs and your back when bending over as far as you can, keeping your legs straight a shoulders’ width apart), you are a Snake. You achieve the performance position using your spinal flexibility alone, not rotating your pelvis at all.

You will like the flat, narrow and long shape of the Tundra.