Use two in conjunction with one 81-47 medium-duty upper rudder gudgeon, or one 81-48 medium duty lower rudder gudgeon and an 81-49 J24 Pin with Clip. Recommended for boats to 25'.Hole Diameter: 1/2"Strap Length: 4 1/4"Strap Thickness: 1/8"Strap Width: 1"Fasteners: Requires four 1/4" RHMSWeight: 2oz.