Setirostris eleryi is a very small microchiropteran, with a light build, and was regarded as tiny when compared to species of Mormopterus, the genus of smaller bats in which they were variously placed.
They have a mean weight of 5.2 g (0.18 oz), a maximum weight of 8 g (0.28 oz) and a forearm length from 31.5 to 36 mm (1.24 to 1.42 in).
The face and muzzle are relatively long and narrow.
The muzzle and face are sparsely covered in fine hair, with the exception of a unique series of 26 to 30 conspicuous bristles on each side and a fringe of fur on the upper lip.

The ears are triangular and are not joined across the forehead and the tragus is rounded.
The dorsal colour ranges from sandy-brown to grey-brown with lighter coloration on the ventral surface.

A prominent long and slender genital projection is present in both the male and female of the species.
The function of the projection is unknown and these features are not shared by any other Australian Chiroptera with the exception of Micronomus norfolkensis.
Males of the species also possess unique serrated lateral flanges on the acutely pointed glans penis.
Features of the dentition are also unique to this species.

As the type and currently sole species of genus Setirostris, S. eleryi was distinguished from other species of the genus Mormopterus by the absence of a developed gular sac, possessing two (rather than three) lower incisors and two (not one) upper premolars.
Setirostris eleryi is a very small microchiropteran, with a light build, and was regarded as tiny when compared to species of Mormopterus, the genus of smaller bats in which they were variously placed. They have a mean weight of 5.2 g (0.18 oz), a maximum weight of 8 g (0.28 oz) and a forearm length from 31.5 to 36 mm (1.24 to 1.42 in). The face and muzzle are relatively long and narrow. The muzzle and face are sparsely covered in fine hair, with the exception of a unique series of 26 to 30 conspicuous bristles on each side and a fringe of fur on the upper lip. 
The ears are triangular and are not joined across the forehead and the tragus is rounded. The dorsal colour ranges from sandy-brown to grey-brown with lighter coloration on the ventral surface.
A prominent long and slender genital projection is present in both the male and female of the species. The function of the projection is unknown and these features are not shared by any other Australian Chiroptera with the exception of Micronomus norfolkensis. Males of the species also possess unique serrated lateral flanges on the acutely pointed glans penis. Features of the dentition are also unique to this species.
As the type and currently sole species of genus Setirostris, S. eleryi was distinguished from other species of the genus Mormopterus by the absence of a developed gular sac, possessing two (rather than three) lower incisors and two (not one) upper premolars.
Setirostris