1,sleeve assembly: match three common shaft sizes:12mm, 16mm,20mm, 5/ ... provide the high quality sealing products1,a convoluted elastomer bellows2, sleeve assmebly: match common shaft sizes: 12mm, 13mm, 15mm, 16mm ,17mm ... steel, alumina ceramic,graphite carbon,NBR rubber bellows. or HNBR, Silicon carbide.5, high volume use in low pressure, small diameter rotary ...