The Aquila 7U Concert Ukulele Strings a set to be a regular tuning in the Key of C : G, C, E and A from bass to treble. They're made in Italy of nylgut which is a polymerized plastic with additives patented by Aquila. 

Approximate Gauges
1 – .0243″
2 – .0305″
3 – .0373″
4 – .0265″