"The Sophia tremolo’s design is such a vast improvement over previous systems that it’s an understatement to call it the most significant tremolo system upgrade introduced since the Floyd Rose." Guitar World
Sophia Stabilizer Spring x 2 -- Set of Two Springs
Original -- Light to medium firm for Drop Tuner
HD Perfect for Sophia 2:92 Seven Tremolos
HD Perfect for Increasing Upward Pitch Change Range with Drop Tuner [on six strings / light tensioned Sevens]
Sophia Original and HD Stabilizer Spring Set Upgrades