This is a single low D ukulele string for baritone ukuleles, which is unwound. As the name of this series of ukulele strings suggests, the string is coloured red. It is just a single string, not a full set of red strings. The Aquila code is AQ-74U.

Wound ukulele strings have a shorter lifetime, can sound too bright and intrusive and have excessive sustain, together with the noise they can make when your fingers or pick strike them. Aquila have now found a method to produce these strings unwound by adding red copper powder to their nylgut strings. This gives an unwound string very good elasticity and fine intonation. For the first time you can get an unwound ukulele string without having to use stiff fluorocarbon.