25, 30, 36, 39, 44, 46 & 50 = piston diameter in mm
E= Emulsion shock absorber D= High pressure gas type shock absorber with internal reservoir in the main body P= High pressure gas type shock absorber with external "piggy back" reservoir H= High pressure gas type shock absorber with hose mounted external reservoir Q1= Progressive damping shock absorber with two pistons W= Shock absorber delivered without spring (spring needs to be ordered separately)