SALT LAKE CITY — The world’s largest trade show for outdoor gear is back in Salt Lake City for a four-day run.

More than 1,300 manufacturers and suppliers are packing every square inch of the floor of the Salt Palace convention hall, plus three outdoor tents, as the Outdoor Retailer Summer Market opens Wednesday.

Organizers expect more than 25,000 people to attend, mostly retailers, who are placing orders for inventory.

It’s a showcase of technology for everything from socks that can take a beating to water bottles that feature battery-powered ultraviolet purifiers.

The makers of a pint-sized but powerful hydrogen battery say it can give a cell phone five full charges before it needs a recharge itself.

Also on display are featherweight canoes, kayaks and stand-up paddle boards.

The summer and winter trade shows have been a mainstay of Salt Lake City since 1996.