The PQL-7004-00 is a perfect option to upgrade the string retainers on your guitar.  They will fit on any guitar that uses string retainers and will help improve the tone and tuning performance of your guitar. (Package contains a pair of string retainers) One of the key causes of tuning frustration is string binding at the nut.  TUSQ XL is impregnated with PTFE, the slipperiest substance on earth and alleviates the binding grip the nut has on the strings.  Strings simply glide back into tune! TUSQ XL is engineered from the same material as TUSQ and is impregnated with PTFE which is five times more slippery than graphite.  It has all the tonal benefits of TUSQ, bringing out the hidden harmonics of your guitar all while drastically improving tuning performance.   TUSQ XL is consistent from piece to piece, and within each piece, to offer you harmonically rich tones without the problems associated with natural materials.   Consistent quality   Impregnated with PTFE   Vintage correct color   Increased harmonic content   Improved tuning          Measure  Length Width  Height  inches 0.462"  0.280"  0.302" inches 15/32" 9/32" 5/16" millimeters 11.70mm 7.12mm 7.65mm      HOW DOES IT SOUND? With TUSQ XL you will hear more richness from every note you play.  Engineered from the same material as our highly esteemed TUSQ, it has all the tonal benefits of TUSQ, bringing out the hidden harmonics by transferring your strings vibrations efficiently to the guitar.  TUSQ XL is consistent from piece to piece, and within each piece, to offer you harmonically rich tones without the problems associated with natural materials.