Both Model S and Model M achieve ISO 23351-1 Class A 35 dB, with identical acoustic, sensor, lighting, ventilation, materials, and certification specifications. Model S is designed for individual use (1 person). Model M is sized for 1–2 persons, making it appropriate for deployments where the single-person pod will occasionally be used for two-person conversations — coaching sessions, one-to-one development reviews, paired call work, or confidential discussions. If the deployment will be exclusively individual use, Model S is sufficient. If there is any anticipated use for paired or one-to-one work, Model M provides that coverage with identical acoustic performance.