The connector comprises an insulated housing (50) (see Figure 5) and contact members (15) housed in recesses (52) therein. Each contact member (15) is formed by U-bending a slotted blank (10) (see Figure 1) and has aligned insulation displacement slots (13) (see Figure 1) and a spade terminal receiving slot (14) in its bend. The insulation displacement slots (13) are relatively wide mouthed (as at 17) and taper to a narrow section (23). Tooth-like projections (21) are provided on opposite sides of the entrance to the narrow sections (23) of the slots (13) for piercing the insulation (35a or 35b) (see Figures 3 and 4) of a conductor introduced into these slots. τhe contact members have protrusions (25) adjacent the narrowed sections (23) of the slots (13) to slightly widen and strengthen the slots (13) and to act to separate the insulation (35a or 35b).