The Hublot Big Bang reference 301.SX.130.RX is the steel-cased expression of the watch that redefined Hublot's modern identity — the original Big Bang, launched in 2005 by then-CEO Jean-Claude Biver as a 44mm fusion of materials that pulled Hublot from a niche rubber-strap brand into one of the most commercially dominant Swiss houses of the past two decades. The 301.SX is one of the most enduring references in the line, presented in fully brushed and polished stainless steel with the signature porthole bezel secured by six H-shaped titanium screws. The 44mm case measures 14.60mm thick and is fitted with an anti-reflective sapphire crystal, framing a matte black dial with chronograph layout — central seconds, 30-minute counter, 12-hour register, and a date window at 4:30. Powering the chronograph is the Caliber HUB 4100, a self-winding chronograph movement built on a Sellita base with Hublot finishing, beating at 28,800 vph with 27 jewels, 252 components, and an approximate 42-hour power reserve. The watch is fitted on a structured black rubber strap with stainless steel deployant buckle — a signature pairing introduced by the Big Bang collection. Water-resistant to 100 meters. A 2009 example, sold as a full set with original box and papers.