The Radian model 1292 4" premium diaphragm fits into TAD™ model 4001 and 4002 2: exit compression drivers. It provides owners of TAD™ 4001 and 4002 compression drivers a cost-effective alternative to diaphragm replacement. The Radian model 1292 diaphragm is fabricated using an aluminum alloy dome, a Mylar™ surround and a Kapton™ voice coil former. Available in 8 or 16 ohms.