The HSI is a single-sided headset designed for use when hearing protection isn’t required, when you still need to communicate with your team but you don’t need the full hearing protection/enhancement that they Clarus earbuds offer.
The headset is mil-spec ruggedized, yet very simple to use and relatively inexpensive. Just unplug one headset at the quick disconnect on the uplead from the control box and plug in the other headset. Many operators have the HSI stuffed into the cargo pocket of their tactical pants to switch out with the ear buds as the operating environment warrants.
Want to try before you buy? Contact your sales rep!