The lowest mass observed for a nucleus of a planetary nebula (NPN) is about 0.55 M⊙ (Weidemann and Koester, 1983, Schonberner, 1983). Hence, Lower mass WD's should have been produced without going through the phase of a visible PN ejection. Recently, Harpaz et al. (1987), have shown that very low mass WD's (up to 0.45 M⊙) can be formed by a single star evolution from red giant branch (RGB) stars, due to mass loss along the RGB. It turns out that WD's in mass range of 0.46–0.55 M⊙ formed by a single star evolution should be formed from the AGB, without an observable PN.