I found this on the
United Travel Options bundles FAQs:
United Club℠ trip pass: A United Club trip pass grants access to all available United Club locations operated by United Airlines (at the departing, connecting and arriving airports) for the direction of travel. Go to a United Club location and a United representative at the front desk will scan your boarding pass. You can enter and exit the United Club location multiple times at no additional charge.
I bought the $40 pass for a PDX-ORD trip. Seemed worth the $ for two visits.