The Arley Z4/Z4 Plus is a handsfree, wearable breast pump designed for convenience and discretion. Its slim fit allows it to be worn comfortably under clothing, enabling mothers to pump on the go. It is available in two flange sizes, 24mm and 27mm, to ensure a proper fit for optimal milk expression. The pump operates hands-free, allowing for multitasking while pumping. It features multiple expression modes and suction levels to cater to individual needs and preferences. The Z4 Plus model generally includes enhanced features such as a longer battery life or additional massage modes compared to the standard Z4.