Hong Kong trams, or ding dings as they're affectionately known, are cultural icons and have inspired a devoted following of tram enthusiasts.
Ricky Lau and Joseph Tse are two of the city's most impassioned. The pair not only founded the Amazing Ding Ding website and Facebook page, they published a series of Chinese-language books on local trams and their history last year.
Lau, a retired exporter, had a reputation as a collector of tram paraphernalia before launching Amazing Ding Ding - among the many items in his cache are more than 100 vintage tickets.
Collecting tram tickets is not unusual in Hong Kong but Lau's collection is special.
While most enthusiasts focus on lucky numbers or tickets with sentimental significance, he amassed tickets with a nearly obsessive zeal, slowly building up entire series for every tram route and number he could get his hands on.
"Some came from my friends, some from antique shops, and some are from eBay," Lau says. "Gradually, one by one I collected. I've got many many [tickets], about 30 rare ones and about 100 common ones."
As a child, he swam every day and would catch a ding ding by himself for an early morning ride to the nearby public pool. Lau says he never lost his love for the mode of transport. "Later, I still loved to travel in the ding ding instead of the bus."
Tse, a proofreader for a financial company, wasn't much of a collector but, like Lau, became fascinated with trams as a boy.
He grew up near the Whitty Street tram terminus in Western district and would sketch his favourite trams.
"Around 4am or 5am I would hear the ding ding sound. It would wake me up so I tried to find out where the [sound] was coming from. When I saw them, with their advertising painted on the side I thought, 'wow so colourful'."
The distinctive sound made by double clangers has been closely identified with the beloved trams and there was a public outcry when its operator at the time, Wharf Holdings, replaced the bells with beepers in 2000. The ding-ding bells were reinstated.
Lau and Tse don't like the modern trams phased in by Veolia Transport, which bought Hong Kong Tramways in 2009. Among other changes, the French owners replaced benches on the lower deck with two rows of individual seats, swapped old turnstiles that would snag passengers' bags with more convenient swing gates and used aluminium instead of wood frames.
"I much prefer the older style. To me, with all the modernisation, it is not a tram any more," Tse says, likening the new models to light rail cars.
Lau agrees. "The traditional ding ding is better than the improved tram. Of course, the modern ding ding is more comfortable than the ones before, but if you want an icon of Hong Kong, you have to choose the traditional ding ding."