Cefaly® II - Hypoallergenic Electrodes £24.00 Add to Wishlist Quantity Add to cart Set of 3 multi-use hypoallergenic (blue gel) electrodes for the Cefaly II and Cefaly Dual device. Product Description Set of 3 multi-use hypoallergenic (blue gel) electrodes for the Cefaly II and Cefaly Dual device.