Some things are compatible with nothing. We may be able to offer possibilities if you post a link to the site that sells it and photos of the pieces of yours (especially the threaded ends). Is it 2-piece (battery cartomizer) or 3-piece (battery atomizer cartridge)?
I found the site. ridiculous prices. Looks like a $20
ecig DSE103 or which can also use RN4081 atomizer w/ RN4081 cartridges OR can use RN4081 cartomizer (if the atomizer's metal mesh bridge /\ does not poke up out of the round atomizer part then that makes it like RN4081 rather than DSE103)
OR - it could be the looks-like-RN4081-but-fits-nothing model
Try some Npro cartos from
njoy (or some 7-11's carry them as 2-n-1 cartos), or some Hendu cartomizers from Smokstik or some of the cheap Chinese prefilled RN4081 cartomizers from AZSmokeFree.com. If those work then you can use those or any other RN4081 cartomizers (not a lot), or you can use RN4081 atomizer w/ RN4081 cartridges, or DSE103 atomizer with DSE103 cartridges