THIS little gem is your ticket to train travel.
Opal card facilities went live at western line railway stations on Friday to give commuters access to cheaper travel.
An Opal card-holder travelling from St Marys can buy a one-way ticket to the city for $6.30, which is 50¢ less than a paper ticket.
More than 100,000 commuters have made four million journeys by train, ferry and two bus services since it was first implemented last June.
Opal ticket facilities are now available at 120 stations throughout the rail network and more than 5000 bus services will join the Opal card system by the end of the year.
Transport Minister Gladys Berejiklian used her Opal card for the first time on Friday when she visited St Marys.
"I appreciate how much people in St Marys rely on the public transport," she said.
"They will save money, it's more convenient and they'll never have to queue again."
Londonderry MP Bart Bassett added: "The Opal card has benefits for people who use trains on a daily basis."
Opal card holders get free travel for the rest of the week once they've made eight journeys.
Commuters who usually get $52 weekly tickets to the city could save up to $16.
"One of my staffers travelled here today at no cost because she uses the card every day," Ms Berejiklian said. "Frequent commuters can go to Sydney Harbour, the Blue Mountains or the central coast for the weekend for free."
Station officers told the politicians that while many commuters are keen to learn about the Opal Card, those without computer access aren’t interested.
Commuters can top up their card online using a credit or debit card.
Cash op up vending machines at train stations and newsagencies will soon be rolled out.
An Opal card cash outlet is already available at a Werrington convenience store.
For commuters who don’t like change, they will still be able to buy paper tickets.
There’s no date on when paper tickets will be phased out.
Opal card features and how it works
*Opal is pay-as-you-go system so only pay for when you use public transport
*To ensure the right fare is deducted, Opal card holders need tap their card on the card holder at the ticket barriers at the start and end of their journey
*Rewards for frequents travel, dscounts for off-peak travel and daily fares capped at $15.
*Opal single fares up to 13 per cent cheaper than paper train tickets
*Travel all you want on Sunday and pay no more than $2.50.