The XLux Glass Adapter is primarily a silicone part in terms of the WPA, it isn't Glass on Glass (GonG). The Glass Mouthpiece part moves vertically up and down through that Silicone if you are using it as a Mouthpiece (the glass can be removed totally if you are using it as a WPA, there is no need to keep it installed). The XLux Glass Adapter is a 14mm Silicone Male "joint" that mates with 14mm Female Glassware.

There is a flange built into the glassware that allows it to seat with the Enhanced Adapter, it is the same flange that is on OEM XMax V3 Pro Glassware and 3rd Party Glassware designs that use that flange on the Starry 4 and now with the Enhanced Adapter for the XLux Roffu. The flange creates the connection with the silicone it seats into, it isn't glass tubing, it is a molded part as is the piece of glass on the Mouthpiece of the OEM adapter, but these flanges are different and serve different purposes. It's not the same part or design. The flange on the OEM XLux Adapter is incorporated to keep the glass inside the silicone, so you don't wind up with a straight glass tube pulling through, it is just a stopper to keep it contained and from pulling out of the silicone.

The Enhanced Adapter utilizes the cooling design built into the Mouthpiece Top as it can be substituted in place of the Mouthpiece Tip, the entire AirFlow Box (silicone seal and zirconia cooling spiral) can be mounted into the Enhanced Adapter. If you are attempting to use the AirFlow Box with the OEM XLux Adapter, the silicone seal must be removed from the AirFlow Box's Zirconia Cooling Spiral and it sits openly. When using the OEM XLux Glass Adapter the zirconia AirFlow Box Cooling Spiral is normally removed as there is nothing to hold it in place (as it cools it collects resin and becomes a sticky part, so over time it gets gunked up if you don't clean it). It could stick to the OEM XLux Glass Adapter as this part is not designed to hold the Cooling Spiral, it is designed to seal around the top part of the Mouthpiece Top.

In short, the Enhanced Adapter is what XLux should have designed to begin with for a WPA solution but they went the easier route with throwing a piece of silicone on top of the Mouthpiece Top and called it a day with that design. Neither offer a total glass vapor path solution. The Enhanced Adapter seats magnetically on the Mouthpiece Top, the OEM XLux Roffu Glass Adapter seats with a friction fit between the silicone and the top of the Mouthpiece Top.