These are the watches worn by the most powerful CEOs in the world

"A watch is the greatest icebreaker there is," says Hamilton Powell, the CEO of Crown & Caliber, an online secondary market for luxury watches.

"In an unfamiliar city, I can approach a complete stranger and with two words eradicate any barriers," he tells Business Insider. "Nice watch."

"A watch tells people about the type of person you are and what you value," Powell adds. "The guy who wears a blinged-out gold-diamond Hublot is very different than the guy with a vintage stainless-steel Zenith chronograph."

With the help of Crown & Caliber, we've put together a list and commentary about the wristwatches worn by 11 CEOs of some of the world's most powerful companies.

Catherine Rice contributed reporting.

Doug McMillon, president and CEO of Walmart

At 50 years old, Doug McMillon is the youngest CEO on this list. He has been the president and CEO of Walmart since February 2014. Before serving in this capacity, McMillon was the president and CEO of Walmart International, "a fast-growing segment of Walmart's overall operations."

According to his company profile, Walmart is visited each week by nearly 260 million customers in 11,529 stores and online. Walmart is the world's largest employer with over 2.3 million associates. In 2016 its revenues totaled $481.1 billion.

Citizen Skyhawk A-T JY0000-53E — $479

McMillon wears a Citizen Skyhawk in the previous slide. And, not surprisingly, the watch, which retails for $479, can be purchased on Walmart's website.

Jeffrey Immelt, CEO of General Electric

Jeffrey Immelt has been the CEO of the industrial giant General Electric for more than 16 years. He has been frequently recognized for his success as a CEO. His company profile says he's been named one of the "World's Best CEOs" three times by Barron's, and since he began serving as CEO, GE has been named "America's most Admired Company" in a poll conducted by Fortune.

With a market cap of over $250 billion, General Electric is one of the largest public firms in the world. In 2016 its revenues totalled $123.7 billion

Breitling Chronospace M78365 — $6,650.00

The experts at Crown & Caliber identified Immelt's watch as a Breitling Chronospace. A similar model can be purchased pre-owned on its website for $3,780. The watch retails for $6,650.00.

Mark Fields, president and CEO of Ford

Mark Fields has been the president and CEO of Ford Motor Co. since July 2014. According to his company profile, since Fields assumed his role he has pushed the company into "emerging opportunities" such as autonomous cars, data, and analytics.

Ford is one of the largest automakers. The Ford F-150 is the most popular vehicle in the US.

Jaeger LeCoultre Master Reserve de Marche Q1488104 — $9,350

According to Luxury Bazaar's website, the watch Fields is wearing in the previous slide retails for $9,350. But it is not currently available for purchase. A model with a similar face can be purchased on Crown & Caliber's site for $5,750.

Tim Cook, CEO of Apple

With a market cap of over $700 billion, Apple is the world's most valuable company. And the man at the helm of it all is Tim Cook. He assumed the position as CEO in 2011.

According to CNBC, Cook "has overseen a rise in Apple's share price of more than 175 percent since being named CEO in August 2011. That's better than the S&P 500, Nasdaq and Dow over the same time period."

Apple Watch — $269

Cook is rarely seen without his Apple Watch. You can purchase one here on Apple's website. They retail starting at $269.

Akio Toyoda, president of Toyota

Akio Toyoda is the president of Toyota Motor Corp., the world's largest automaker, a post which he has held since 2009. Before that, he was appointed to the board of directors in 2000 and promoted to executive vice president in 2005.

According to his company profile, he received his MBA from Babson College in 1982 and joined Toyota (TMC) in 1984. In its most recent fiscal year, Toyota made 8.7 million vehicles and pulled in $19 billion in net profits, which represents a 6% increase from 2015.

Patek Philippe Calatrava 5119G — $21,500

Toyoda has been photographed numerous times wearing what the team at Crown & Caliber expect to be a Patek Philippe Calatrava. This watch retails for $21,000, but watch lovers can purchase it pre-owned for $16,860 on C&C's site.

John Watson, CEO of Chevron

John Watson is the CEO and chairman of the board of Chevron Corp., a post he has held since 2010.

He received his MBA from the University of Chicago Booth School of Business and joined Chevron in 1980, serving as its CFO from 2001 to 2005 and vice chairman of the board from 2009 to 2010.

Chevron is an energy corporation that produces natural gas and geothermal energy, as well as alternative-energy research and operations such as solar, wind power, and biofuels. And with a market cap of over $200 billion, it is one of the largest publicly traded firms.

Breitling Aerospace E79362 — $2,590

Watson's watch can be bought on Crown & Caliber pre-owned for $2,590.

Randall Stephenson, CEO of AT&T

Randall Stephenson is the chairman, CEO, and president of AT&T, the multinational telecommunications firm. In addition to its flagship brand, AT&T, the company owns DirectTV, Cricket Wireless, and Roots Sports. With a market cap of over $250 billion, AT&T is one of the largest publicly traded firms.

Stephenson has been the firm's CEO since 2007. Last year he was named CEO of the Year by Chief Executive magazine.

TAG Heuer Kirium CL111A — $415

A pre-owned version of the watch Stephenson is sporting in the previous slide is going for $415 on eBay.

Michael Corbat, CEO of Citigroup

Michael Corbat is CEO of Citigroup, one of the world's largest banks, a post he has held since 2012. Corbat has been at Citi since he graduated from Harvard University with a degree in economics in 1983, as CEO of Europe, the Middle East and Africa, overseeing all business operations, head of Citi's Global Corporate Bank and Global Commercial Bank, and before that CEO of Citi Holdings.

Jaeger LeCoultre Master Perpetual Calendar Q149242A — $11,500

In the previous slide, Corbat was photographed wearing a Jaeger LeCoultre Master Perpetual Calendar. The watch goes for $11,500 pre-owned on Crown & Caliber's site.

John Hammergren, CEO of McKesson

John Hammergren is chairman, president, and CEO of McKesson Corp. He was elected president and CEO in 2001 and chairman in 2002. Before joining McKesson in 1996, he worked for Kendall Healthcare Products, which was later sold to Tyco Healthcare. McKesson is a leading provider of healthcare services, distributing pharmaceuticals, and providing information-technology solutions to improve healthcare.

According to his company profile on McKesson's website, the company has more than quadrupled its revenue to $190 billion since Hammergren became CEO.

Rolex Submariner 116610 — $8,360

Hammergren's watch is going for $8,360 pre-owned on Crown & Caliber's website. If you want it, then you better act fast as there is one left in stock.

Dieter Zetsche, chairman of Daimler

Dieter Zetsche has been chairman of the board of directors of Daimler AG, the multinational automotive corporation, and head of Mercedes-Benz cars, since 2006.

He was named in Time magazine's list of 100 most influential people in 2006. He holds a doctorate in engineering from the University of Paderborn.

Chopard Mille Miglia GMT Chronograph 16/8992-3001 — $6,140

Zetsche's watch retails for $6,140 but can be purchased on PrestigeTime.com for $4,420.

A similar model can be purchased pre-owned on Crown & Caliber for $2,940.

Jeff Bezos, CEO of Amazon

Jeff Bezos is the founder, chairman, and CEO of Amazon.com. Bezos ranks as the fifth-richest person in the world with an estimated net worth of $71.8 billion in January 2017, according to Forbes. In 2013, Bezos purchased The Washington Post for $250 million.

Amazon's stock has been climbing because of the proliferation of Amazon Web Services, Amazon's cloud-computing service. Its market cap stands at over $400 billion.

Ulysse Nardin Dual Time 233-88-7 — $7,700

Bezos has been photographed frequently wearing at Ulysse Nardin Dual Time. It retails for $7,700 new but can be purchased pre-owned on Crown & Caliber for $4,150.