These are UBASS strings, made for Kala in LaBella in the USA. They are made with a steel core, with steel flat wound wire. The flattwound tape makes them smooth to the touch. They are designed for solid body UBASS models (i.e. not for electro acoustic instruments). They’re intended to work with magnetic pickups.

These are for regular bass tuning, EADG, suitable for a 23.5” length. The gauges are:  .049 (1.24 mm), .069 (1.75 mm), .89 (2.26 mm), .109 (2.77 mm)

These strings tend to be quite pricey, but they are really popular, giving a slightly more double-bass like tone than the roundwound strings Kala also do.

I can only send these strings within the UK, except if ordered with an instrument. UK shipping is included in the price.