Well, its actually two attachments from amazon. There are actually a few different options on there IF u look up water honey straw. . Just re purpose the bubbler section and use it w ur Regen. Waay cheaper than say a hydrotube. It was like 30$. There are also some nice looking silicon honey straws w glass perc chambers that look like they would work well too. Here's the Magic trick.. just get this little darling. https://www.amazon.com/dp/B07TQ443G8/ref=cm_sw_r_cp_apa_i_-8ivFbZ24YGBD

Its called a Hemper A-Dab-Ter its 10$ it fits perfectly on the regen cap , and the other end fits pretty much anyrhing..

HEMPER A-Dab-TER | Silicone Vape Pen Adapter for Water Pipes | Round & Flat Tips (Purple) https://www.amazon.com/dp/B07TQ443G8/ref=cm_sw_r_cp_api_i_xgmcFbMSAABXD

10 dollars off amazon brother! I just think you’d have a better expierence w a full seal and a designated piece for it! I always clean my main bong for flower but it always smells bad after a day or two of use and wouldn’t want to use my pen with mine.