The Air Tight Disc Flatter uses warmth and pressure to restore the flatness of LPs. An LP is centered between the marks on the Disc Flatter and the top is closed and locked. The LP is now sandwiched between two glass plates. Set the timer and low power heating elements slowly bring the LP up to the optimal flattening temperature; with heat distributed to the most commonly affected areas of the record (the label and record edges). The timer on the Disc Flatter allows for flattening times from 30Mins up to 120Mins, but in our experience, there’s no harm done to the LP no matter how long it’s in the Disc Flatter, so we routinely set it to 120Mins.
via MUSICDIRECT – AIR TIGHT – DF-01U DISC FLATTER. actually via our friends at Analog Apartment