Gotoh Stealth Keys are the smallest and lightest tuning keys on the planet! Only 11.9 grams (.026 lb) each! That is equivalent to 1/2 to 1/3 of the weight of ordinary guitar machine heads. These machine heads let the instrument resonate to it's fullest potential and reduce the weight of your guitar significantly. Don't be fooled by the size and weight, these are made to last using high quality aluminum alloy, stainless steel, and brass materials.
18:1 Gear Ratio (Micro Worm Gear) 6-In-Line (String tension must be less than 20kgs or 44 lbs) In other words don't use anything over standard light gauge strings.