Lenzner Supersolo Classic 1310 B 3/4

These Lenzner gut strings are good value for money. Whilst not cheap, by gut string standards they are not expensive; some of the higher end gut strings are well over £400 for a set. They don't have quite the quality and nuance of tone that you would get from these but they do the job and provide a sound and feel which is definitely 'gut'.
As with all gut strings they need a bit of care and do not appreciate harsh conditions (too cold or too hot). It is worth bearing in mind that most basses will benefit from various adjustments (small and large) to make the most of gut strings. They are a lot thicker than steel strings and string grooves, heights and tensions may need to be adjusted.
I had a set of these on a bass for a couple of years and I remember that after about six months they had settled down and stayed reasonably in tune. (Bear in mind that when first fitted they will need retuning every 5-10 minutes and even after a few weeks they may need retuning several times during a gig/concert.)
Gut strings are more prone to break so it really is advisable to also have a spare set!