(IDEX Online) - Rolex reportedly paid a record $2.5m at auction to buy back one of its own watches.The 1958 Milgauss steel sports watch, described as being in mint condition, smashed the estimate of $556,000 to $1,110,000 when it sold at Phillips Geneva.The buyer's identity has not been confirmed, but Bloomberg says the winning bidder bought the watch on behalf of Rolex, probably for its archive.The Milgauss was specially designed for scientists at Geneva's Conseil Europ?? (C)en pour la Recherche Nucl?? (C)aire (CERN) working in labs with high levels of electromagnetism.Its soft iron cage allowed it to withstand exposure to 1,000 gausses (a measure of magnetic flux density). So the name Milgauss, from the French 'mille gauss', or its nickname, "the mad scientist's watch".Phillips described it as "The probably best preserved and to our knowledge complete amagnetic stainless steel wristwatch with honeycomb dial, 'lightning' hand, bracelet, chronometer certificate, guarantee, hang tag and presentation box."Pic courtesy Phillips