Datavideo ITC-100SL Additional Beltpack For ITC-100 Intercom SystemThe ITC 100SL Additional Beltpack from Datavideo is the same beltpack as the 4 that come included with the Datavideo ITC 100 intercom system. It can be used as a replacement or to expand the system. The ITC 100 intercom system supports up to 8 of these beltpacks in total. The beltpack features a 5 pin XLR input for talkback, power, and tally, and 3. 5mm and 2. 5mm headphone jacks for standard or Motorola type headphones. It has call and talk buttons,