The String Mute "M" with 18 - 20 cm ( 7,08 " - 7,87" ) total length , padding size 6 - 7,5 cm ( 2,36" - 2,95" ) fits for  5string basses and classical guitar. 

• No tooling necessary 
• Adjustable hoop & loop strap allows fine-tuning of string pressure
• effectively dampens overtones, resonating empty strings and sympathetic resonances during recordings, live performances, or two-hand tapping
• MEDIUM : Fits for 5string bass and classical guitar

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. 

• No tooling necessary 
• Adjustable hoop & loop strap allows fine-tuning of string pressure
• effectively dampens overtones, resonating empty strings and sympathetic resonances during recordings, live performances, or two-hand tapping
• SMALL : Fits for 4string bass, 6string Electric guitar and Ukulele