in order to capture these sliding sounds. Around 2007, a new type of strings were produced made of mostly a nylon core coiled with nylon like the metal-nylon strings, possibly in imitation of Western catgut strings. The sound is similar to the metal-nylon strings but without the metallic tone to them (one of the main reasons why traditionalists do not like the metal-nylon strings). The nylon strings can be tuned to standard pitch without breaking and can sustain their tuning whatever the climate, unlike silk. The strings have various names in China, but they are advertised as sounding like silk strings prior to the 1950s, when silk string production stopped. Traditionally, the strings were wrapped around the goose feet, but a device has been invented, which is a block of wood attached to the goose feet, with pins similar to those used to tune the guzheng protruding out at the sides, so one can string and tune the qin using a tuning wrench. This is good for those who lack the physical strength to pull and add tension to the strings when wrapping the ends around the goose feet. However, the tuning device looks rather unsightly and thus many qin players prefer the traditional manner of tuning; many also feel that the strings should be firmly wrapped around the goose feet in order that the sound may be "grounded" into the qin; and some feel that the device which covers the phoenix pond sound hole has a negative effect on the sound volume and quality. Tuning To string a guqin, one traditionally had to tie a fly's head knot (yingtou jie) at one end of the string, and slip the string through the twisted cord (rongkou) which goes into holes at the head of the qin and then out the bottom through the tuning pegs (zhen). The string is dragged over the bridge (yueshan 『岳山』), across the surface board, over the nut (longyin dragon gums) to the back of the qin, where the end is wrapped around one of two legs (fengzu "phoenix feet" or yanzu "geese feet"). Afterwards, the strings are fine-tuned using the tuning pegs (sometimes, rosin is used on the part of the tuning peg that touches the qin body to stop it from slipping, especially if the qin is tuned to higher pitches). The most common tuning, "zheng diao" 〈正調〉, is pentatonic: 5 6 1 2