It’s a very recognizable bass. There aren't any others like it. Where the headstock usually is there's a spring-loaded clasp, which holds the string down at E. But when you release the clasp, the E string can go down to D. He was not the first person to make a headless bass, but he was the first to make that string clasp that allowed it to go down to D. Since there were no five string basses around at that time, I chose that one because it had a string that went down to D. Once I got a five string in my hands the Factor wasn't as usable to me because now I could go lower than D!