Collar tabs for the SS-Totenkopfverbände uniform (literally from German: units of the "Death Head", these units were involved in the protection of concentration camps). The skull and number 1 (for the 1st Standarte or regiment) are on the left tab, the right is plain black (by adding pips you can make "lieutenant" ranks: SS-Sturmführer, SS-Obersturmführer, SS-Sturmhauptführer). 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.