IF
You need a y-type cable, look at the cross-reference chart from Hosa.
Y-type cables

In the chart, if you click on model numbers CYM-100 and STP-200, you can see the mono + stereo plug differences (1 ring and 2 ring) that George and Gary referred to.

As Tom said, lower-priced cables can also do the job.
I have bought different types of Hosa cables from local Guitar Center or Sam Ash stores, at lower prices, and they have done the job.

Happy Connections!