The HAI-12 and HAI-12 II are designed for use in Class I, Division II hazardous locations where explosive gases are present, such as rocket launch pads. These units are certified to meet Class I, Div II by an independent third-party laboratory. They feature a sealed enclosure with a front panel designed for personnel wearing protective gear with heavy gloves. Sunlight-readable LCD panels display four pages of 12 line keys (48 line keys). Design features include membrane-protected front panel buttons, two volume control knobs, and a 20W speaker. An optional unit extends headset/handset jacks and basic control functionality to a remote position. The HAI-12 and HAI-12 II connect to the MVP using a T1 line with a KTMX.