The 2187643-1 is a STRADA Whisper 3.9mm 100-Ohm pair-in-row vertical header connector designed for high-speed differential signal routing in backplane applications. This connector supports multiple pair configurations (4-pair, 8-pair, and 12-pair) with optimized impedance control of 100 Ohms for differential pairs. The connector enables efficient layer-specific routing (LSR) techniques to minimize crosstalk and reduce PCB layer count requirements, with 4-pair configurations requiring 2 layers or fewer and 12-pair configurations requiring 6 layers or fewer for signal routing. The design incorporates interstitial transmit/receive pin assignments to reduce noise within the connector pinfield. Material characteristics include a dielectric constant (Dk) of 3.5 with loss tangent (tanD) of 0.007, supporting both 6-9-6 and 7-7-7 routing stackups. This connector is ideal for high-speed interconnect applications requiring controlled impedance, minimal crosstalk, and efficient PCB routing in telecommunications, data center, and high-performance computing environments.