It is one of Alan’s @eboosted single stack enclosures from the Century 40 group buy. I think a double stack is in the works: Eboosted Enclosure - Subsonic Century 40 21700 DS - Group Buy/Gauging interest
but that would probably scrape like crazy on thane.
I was stubborn and wanted 12S4P of P42A cells in 21700 NESE enclosures because I wasn’t ready to learn to weld cells. I ended up using 1" x 3/4" weatherstripping as a gasket to gain the extra space I needed for the battery: https://www.amazon.com/gp/product/B07RXWQ2T7/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
The risers are 35mm thick and are sold for mountain boards: https://www.ebay.com/itm/1-Set-Skateboard-Longboard-Riser-Pad-1-3-8-Black-2PCS-Plastic/362596259571?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649
I really like the way this board rides. NOTHING rattles, it has a subtle spring to it and and the foot pockets are sweet.