TE Connectivity 0.6mm Free Height (FH) Board to Board Stacking Connectors A range of 0.6mm Free Height (FH) board to board SMT stacking connectors for parallel board stacking that achieve different spacings between parallel boards through the combination of the various plug and receptacle heights. These 0.6mm Free Height (FH) board to board SMT stacking plug and receptacle connectors are ideal for use in applications where miniaturization is essential such as notebook PCs, mobile phones and communication equipment.