3M MetPak HSHM Press-Fit Header HSHM Series Manual 3M™ MetPak™ HSHM Press-Fit Header 2 mm Type B19, 95 Signal Contacts, 5 Rows, Straight HSHM Series is a high performance connector that supports 5 Gb/s data rate and features low crosstalk, 50/100 Ω impedance.