Couplers which one?

[Texas438.com]

Rolling stock purchased on eBay comes most time with couplers that need to be changed to Bachmann EZ Mate ll couplers. How can I determine if I need short, long or central shank.

Also, is there a video showing how to change the couplers.

Thanks, I am new at this.

[the Bach-man]

Dear Tex,
The vast majority of conversions require center shank medium.
If that doesn't work, what you need will instantly become apparent.
Simply unscrew one and replace with the next.
Have fun!
the Bach-man

[jward]

Or..... you could look carefully at the photos before you bid, and only buy the ones with Knuckle style couplers. The older horn hook style on cars is often a giveaway that what you're buying is a cheaply made train set car from the 1970s or 1980s. Most of us back then Upgraded those cars worth upgrading with Kadee couplers, that were the standard all other Knuckle couplers are based on. If the cars you're bidding on haven't yet been converted, ask yourself why.

[rich1998]

The OP could check the Kadee site for recommendations or You Tube site for possible videos.
A search will bring up both sites if the OP really likes the cars from ebay.

Rich