Ideal for lowered Softails. Stronger than stock springs; prevent bottoming out. Big Red springs are recommended for solo riders; rated for 1200 psi (EU: 8,27 MPa). Big Blue springs are recommended if occasionally carrying a passenger or the rider weight is 220-290 lb. (EU: 99,79 - 131,54 kg) ; rated for 1300 psi (EU: 8,96 MPa). Big Gray springs are for lowered machines that often carry passengers or for the rider whose weight is 300+ lb (EU: 136,08 kg+).; rated for 1400 psi (EU: 9,65 MPa). Fit OEM and Progressive Suspension shock absorbers. Made in the U.S.A..