This medium-sized bat is known from the eastern Andean slopes of Peru and Bolivia. It has a white dorsal line and long, dense hairs on its feet and tail membrane.
The fur is dark brown above and grayish below, with three color bands in the dorsal and ventral hairs. A white line runs along the back; the feet and edge of the tail membrane have dense, long hairs.
A study in the montane forest of Pampa Hermosa, Peru, classified P. masu among nomadic frugivores and reported dietary overlap with Vampyressa melissa. This describes one study site and does not establish travel distances or a range-wide food specialization.
An extinction-risk assessment has not been added yet.