The ORTF Surround arrangement has been designed to be mounted conveniently in a single elastic suspension and (as an option) to share a single windscreen (see WSR ORTF Surround). The windscreen is not comprised with the ORTF Surround Indoor Set.

It differs from the IRT Cross arrangement in being rectangular rather than square. Its pickup regions are correctly apportioned through careful choice of the angles and distances among the microphones.

The ORTF Surround Indoor Set comprises:

• four CCM 41 Lg compact microphones
• a four-way “ORTF Surround Bar“ (ORTF Surround Bar LM) terminated with a Neutrik multi-pin connector
• an elastic suspension (Rycote Invision INV-7)
• a 5-meter, four-way Binder multi-core cable (K Surround 5 M)
• an adapter cable AK Surround M/4U (Multipin / 4 × XLR-3M)

When working indoors, the ORTF Surround Indoor Set is used without windscreen. If a moderate degree of wind protection should be required, a Schoeps B 5 D foam windscreen can be placed over each microphone separately.