To be ergonomic means that something is designed to fit the human body, and Pure Ocarinas place ergonomics as first priority.
The ocarina can be challenging to play, as they have two thumb holes, the second of which must be opened without dropping the instrument. Pure ocarinas provide you with good support points to make it easier for you to play the high notes.
The finger holes on Pure Ocarinas are individually angled to align well with your hand. In particular, the left thumb hole is angled so the finger may rest flat. In order for the 3 point grip to be effective, the left hand must be quite vertical, so the left thumb hole has been angled to make this easier to do.
The right thumb hole is angled to provide positive support to the finger, and a ridge is provided to move the pivot farther from the hole, and make the hole easier to open. The finger hole edges are also softened, to increase player comfort.
Pure Ocarinas are carefully balanced on two planes, primary and secondary. These allow you to support an ocarina with only a few fingers. The balance planes are as follows:
The primary plane runs between the right thumb hole and the right tail of the ocarina. This allows you to support the instrument using only the right thumb and pinky when held parallel to the ground.
The second plane runs between the left pinky hole and the mouthpiece. Note that this plane can only be used when the pinky hole is placed on the side of the instrument.
The mouthpiece of these ocarinas is angled and long enough to provide good, comfortable hand posture, without squishing your hands too close to your face.
The tip of the mouthpiece is also designed to fit your lips, being thin and having a rounded edge. This is especially useful on multi-chambered ocarinas, as it makes it easier to blow the desired windway.
As common ocarina playing technique requires sliding fingers over the surface of the instrument, the surface finish of an ocarina effects how it feels to play.
Pure Ocarinas are offered in plain and shellac finishes. As these have a rougher surface, fingers grip less, and sliding movements are thus easier.
Plain finishes have an additional advantage as ocarinas are made from earthenware, which is is porous. This porosity absorbs finger moisture, which keeps them dry and makes sliding movements easier to do.