Collar tabs for an officer of the SS. There is a couple of "sig" runes on the left tab, the right is plain black (by adding pips you can make "lieutenant" ranks up to colonel: SS-Untersturmführer, SS-Obersturmführer, SS-Hauptsturmführer, SS-Sturmbannführer, SS-Obersturmbannführer). Bullion by silver metal thread. Edge piping is made of a twisted silver-black cord.
How to sew collar tabs on? Put a collar tab on the collar of the service jacket so that it is not less than 5 mm from the edge. Fix it with a bright thread (which then remove) or glue. When collar tabs sit properly, they need to be sewn with a black thread by the edge.