Philips 540-511 TightRail Mechanical Rotating Dilator Sheath, 11 Fr X 18.7" / 47.5 cm Size, Device Inner Diameter 11.2F / 0.145" / 3.7 mm, Outer Diameter 18.0F / 0.234" / 5.9 F mm, Outer Sheath Inner Diameter 23.0F / 0.293" / 7.4 F mm. Box of 01