The free-height BTB connector can be effectively used in parallel stacked printed circuit board (PCB) connections. The number of digits provided ranges from 40 to 240, and the contact pitch is 0.5, 0.635, 0.8, and 1.0mm. Combined plug and female end sheath height, can achieve board-to-board stacking height from 3.5mm to 20.95mm Floating BtoB connectors, which are movable in X,Y,Z directions, help prevent mating position errors.