I found Mia on the Bruno Mathsson site and am surprised this is his first chair I share here (?)
Mi 407 Mia
Designed in 1972-1973
Stackable chair with armrests. Fully upholstered over polyether (CMHR) and supporting web. Buttonstitched.
Floor runners with plastic glides.
Information on covering materials on request.
Width 615, depth 580, height 790, seatheight 435 mm.
Fabric needed: 100 cm by 130 cm width.
Leather needed: 2 chairs = 1 hide by 4,5 m2