Thank you for viewing. This is a set of four Pirastro Flexocor orchestra tuning double bass strings. After purchasing strings that were used for a year, I used them for about a year and then removed them for home storage. There are some frayed parts on the string windings due to repeated attachment and removal. There is no fraying on the metal parts. I believe they are usable without any problems, but please understand that they are used items. They give the impression of producing a clear sound with a strong sound pressure. The articulation is good, and there is less strain on the left hand. How about trying them out? Manufacturer: PIRASTRO Type: Flexocor Set of 4 (GDAE)