Never heard that name, but according to their safety data sheet [1] it is 95+ % dimethylformamide [2]. Not too different from acetone, with a additional dimethylamin group. Acetone-free nail polish remover usually contains primarily ethyl acetate [3] which is also structurally similar.
[1] https://bsi-inc.com/sds_pdf/sds_un_cure.pdf
It must be extremely low vapor pressure compared to acetone. Little smell and not an ultra airtight lid. Lasts forever.
Wow, speaking of safety -- I just looked it up to see if Un-Cure superglue/CA debonder would be safe enough to use on hands, or would just cause the chemicals to be broken down and absorbed through the skin at a fast rate too (which I personally wouldn't want), and the initial results I see say that it's ok to use on hands. Wow again.