Aquila Lava Ukulele Strings.Aquila LAVA Ukulele Strings. A grey-black set of strings coloured with a touch of mother-of-pearl inspired by volcanic rocks . Aquila are the best known and one of the top manufacturers of ukulele strings. All sets of Aquila nylgut strings provide a bright, clear and ringing tone. Easy to the fingers and guaranteed to give any ukulele a tonal 'lift'. Aquila LAVA Ukulele strings are Aquila's latest brand based on Super Nylgut in a grey-black colouring specially designed to settle in quickly and give maximum ease of tuning.