Barton Marine's K Cam Cleat is made from a composite Kevlar/Zytal material. Cams utillize stainless steel leaf springs that give a smooth but posiive action. The Midi can accept line from 1/4" (6mm) to 1/2" (12mm) with a holding power of 507 lbs. Requires two 3/16" (5mm) flat-head fasteners (sold separately).