I have a bunch of the older style stainless steel CE2s, which I still use for sampling DIY stuff. The older style middle rings were tapered in the center, around the hole. I've used the newer middle rings, flat side up, and then one of the older, tapered rings, taper side up, and then the drip tip. The extra ring takes up the remainder of the space between the rings and the end of the drip tip. The rings remove very easily for filling.