A smaller flying relative of the flightless predators which have been uploaded earlier. Its limb structure allows it to crawl, hop, climb and leap while launching itself airborn in the process. Please note that the bones are not visible on the live animal, they are there only so that the limb structure can be better understood. The membranes are more similar to the patagia of gliding squirrels than of bats and pterosaurs, but thinner and covered under a thick intergument of short, fine, keratinous "xenofuzz" (gotta love neologisms XD) vhich gives them a velvety look. Flightles species may have utilised these structures for different purposes, from display features to protective spines. The "wing finger" is actually a multipple-segmented foot of the limb, with a comb (notice the difference between a "comb" and a "fan" of radiating terrestrial vertebrate digits) of backwards-oriented digits which give it both, flexibility for great manueverability and structural strength. There are three pairs of airsacks in the body and additional airsacks in the main wing, in the compartments frambed by the bones. There are brush-like rows of shicker hair outlining the backward-pointing wing fingers which make it a more silent and more efficient flier by reducing drag and directing airflow over the wings, reducing turbulence.
I'm reminded somewhat of my aviforms, though I think you did a better job in bringing out its appeal. I'm somewhat confused by the limb arrangement and means of folding, but I won't press you there. I have only two points that I feel need revision; you should have somewhat larger feet or at least additional toes for grasping surfaces while landing (unless this is an oceanic flier or perhaps hooks onto vertical cliff-faces and tree trunks), and I do not think the airsacks in the wing would aid it in flight, as lift coefficient is related to shape and those with best lift coefficient are nearly flat or like airfoils (airplane wings), yet forward drag is related to the forward cross-section and will increase with a thicker wing (unless you're implying that the wing is pockmarked, like a golf-ball; apparently this reduces drag somewhat).
you're maybe right that airsacks in the wings are a bit too much.
I realize this creature would not be a great walker, but it's supposed to be something like swallows, who spend most of their lives in the air