1. Forma lapilli rotundi,
2. Levis, tantum 30g pro tota machina, 2.7g pro singulis auribus, facile portanda
3. Commoda semi-intra-auricularia, sine dolore diu gestanda
4. Orator spiralis mobilis 13mm magnus, trium frequentiarum libratus, qualitatem soni HiFi praebens