The XL Plungers have an extra-wide opening which allows for the suction of an extra-large area. The unique easy-push design creates a powerful vacuum that clings tightly to your flesh. As blood flow to the nipples increases, they will become more sensitive, making play more fun! Made of premium-grade silicone, these suckers are not compatible with silicone lubricants, so it is recommended that you use a water-based lube to create a tight seal.