The whole thing is pretty simple: first, pick a pass type and the number of days you'd like to use it for. The 50-attraction pass (348RMB for one day; 498RMB for two days; and 589RMB for three days) grants you access to one of the city's five 'main' attractions (like the Pearl Tower or the observation deck at Shanghai World Financial Center), and unlimited access to the other 45 'type B' attractions like river cruises or the Jinmao Tower.
After purchasing the pass online, users are then able to scan the same QR code at each different attraction, saving time that'd otherwise be spent queueing at various ticketing counters. There are loads of different options available (with a whopping eight different categories). Check out all your options in Mandarin via C-trip here
, or for a smaller selection of choices in English, search ‘Shanghai City Pass’ on trip.com.