What unit is this?

[Bob Chatt]

I will always admit German items are not my strong point.

But I just had a complete German Dog Tag come in and it is marked :

1./Pi. Ers. Btl. 17

What type of unit is this?
Thank you in advance,
Bob

[naxos]

1. Kompanie, Pionier-Ersatz-Bataillon 17

1st company of the 17th Combat Engineer Replacement Battalion

[Bob Chatt]

Thank you