Specially designed heat resistant carpet mat.  Protects piano from effects of under floorheating.  Also reduces noise levels.

152 x 59 cm

https://www.pianoaccessoryshop.co.uk/product/upright-piano-carpet/

Used only for one year prior to moving house. Being sold as no longer have underfloor heating.  Area near centre is slightlyworn/compressed (see photos 3 & 4) but shouldn’t affect properties.  Photo 2 shows back of mat.  Mat looks slightly wavy due to being rolled up for a while.