Vase is named 'Les Plumes', cat. no. 7050. The design was introduced in 1929 (info from Phillipe Decelle's Sabino: Maître Verrier de l'art deco 1878-1961 Catalogue Raisonne).
While it's unusual to be unsigned, it's not entirely unknown for older Sabino pieces to lack marks. For example, I have a 'Coquilles' vase in an unusual blue cased opalescent glass which is also unmarked.