fits 4string bass, ukulele and 6string electric guitar No tooling necessary Adjustable hoop & loop strap allows fine-tuning of string pressure The String Mute "S" with 16 - 17 cm ( 6,3" - 6,7" ) total length, padding size 5,5 - 6,5 cm ( 2,16" - 2,56" ) fits for 4string bass, 6string electric guitar and ukuleles