I meant Kadee.   My computer auto corrected and I didn't catch it.   Sorry.   My train is N not HO.   My mistake.   I'm totally new at this.  Is there any way I can improve couplers?

I looked at Kareem, they're supposed to be the best.   But I can't determine which number to buy.   There are a lot of options and I don't know much about this.  The Kareem site stated they don't provide info regarding Bachman upgrades.   

Couplers seem flimsy and unreliable.  Can they be upgraded.   How?  What part number?   How difficult?    This is a display, Christmas only train.   But we'd like it to work reliably year after year.