Those Pudgala-skandhas (material aggregates), with innate capacity to undergo subtle transformation, which are possessed of only four types of touch (Snigdha-Rūkṣa (gluey-dry), (śīta-usna (cool-hot). They are neither-heavy-nor-light they are not possessed of weight (mass), e.g. Karmaśarīra (subtlemost body) formed by Karma-pudgalas (material clusters qua Karma)), Manayoga (activity of mind), Vacanayoga (activity of speech).
See - Aṣṭasparśī.