why two 15mm sockets?

[kyoung]

I ordered this yesterday but was curious why there are two 15mm sockets in the set? Maybe a typo?

http://www.tooltopia.com/index.asp?PageAction=VIEWPROD&ProdID=8518

 

[goodfellow]

Probably a Typo -- should say 16mm socket

 

[rsanter]

perhaps they had extras.....

 

[paramudduck]

http://www.dealtime-direct.com/sun2653.html They say it's a 16mm