Both connectors are designed to accept a 1.58mm (0.062”) thick add-in card and molded polarization keys on the connectors and corresponding notches on the add-in cards prevent improper card insertion. Dual-row card edge contacts on 1.0mm pitch are offset to form four rows of through-mount soldertails on 2.0mm pitch for easy wave soldering. The soldertail length supports use on 2.36mm (0.093”) thick motherboards. Metal board-locks provide connector-to-motherboard retention prior to soldering. Connector versions that are compatible with lead-free soldering processes are also available. The resin for the connector bodies is a high-strength thermoplastic compatible with lead-free soldering temperatures. Tin finish on both soldertails and board-locks also aids compliance with lead-free requirements.