Product Description Spinnaker Pole Ring - Curved Base - 30mm(1-3/16") IDFeatures:Suits most common mast profilesGrade 316 Stainless SteelSpecifications:Material Ø: 6.4mm(1/4")Ring Ø: 30.0mm(1-3/16")Mast Ø: 60.0mm(2-3/8")Weight: 45g(1.6oz)