In the scene(s) where Bruce is setting up the Batcave and testing various components of the Batsuit and the devices/weapons he would use, there is a scene where he has what looks like long spars or claws from the fingers of gloves he is wearing.

He was able to stretch them taut, then let them sag by the flick of a wrist. What was that? We don't see it later in the film that I could see. Was it a precursor to one of the devices he uses in the later films?