Single piece.

Length 25 mm / 1 inch.

If you would like a full box, you need to order 10 pieces.

Use of Marklin 8504 Straight Track (25mm)

Here are some applications with the 8504 track.

Adjusting the center-to-center spacing on one side of Circle 1 (8510 curved track).
Note the two standard spacing dimensions of the track (25 mm and 50 mm).

Adjusting the center-to-center spacing on both sides of Circle 1

Adjusting length when installing the curved turnouts other than previously described