STL series adjustable student chair, height group 3-5, on slides

The bottom part of the frame is made of oval thin-walled electrically welded pipe with cross-section 50*30 mm, pipe wall thickness 1,5 mm. To the horizontal lower parts of the frame are perpendicularly welded support parts made of round thin-walled electrically welded pipe diameter: 32 mm, wall thickness of the pipe 1,5 mm. The upper part of the adjusting mechanism is made of round thin-walled electrically welded pipe with diameter: 28 mm, wall thickness 1.5 mm. The upper part of the chair frame is made of a flat-oval tube with a cross-section size of 30x15mm, wall thickness of 1.5mm. The horizontal lintel is made of a round thin-walled electrically welded pipe with a diameter of 18 mm, wall thickness 1.5 mm. Leg support made of oval thin-walled electric-welded tube. The chair is equipped with internal plastic supports."