Aluminium-based, WH (Heeres) ie. 'Pionier-Truppen'-related ID-disc: '1./Pi.20' and that comes mounted onto its period cord as worn

This is a neat - and fully untouched - example of a silverish-coloured- and/or typical aluminium-based, WH (Heeres) ie. 'Pionier-Truppen'-related ID-disc (ie. 'Erkennungsmarke') that is bearing the clearly stamped unit-designation that simply reads: '1./Pi.20' (and as such being a disc that was I deem intended for a soldier or NCO who served within the: first company of the 'Pionier-Bataillon', numbered: '20' (which belonged to the 20th Infantry-Division) and that comes in an overall nice- (albeit clearly used ie. worn-), condition. The disc is executed in an attractive letter-type and shows the clear evidence of having been used ie. worn (it shows somewhat torn-out holes as can be seen on the pictures). The disc shows a clearly stamped bearers'-blood-group-type (Type A) something that is more often observed: of interest is, moreover, the fact that this bloodgroup-type was unusually period-corrected (something that I have not seen before). The disc originates from a private-household in Germany where it was recently uncovered. Simply an attractive and honest WH (Heeres) ie. 'Pionier-Truppen'-related ID-disc that is I deem accordingly priced!