The 30mm sheave box is a top-performing solution designed to enhance the efficiency and longevity of your rigging system. With a removable axle pin, maintenance or replacement of sheaves is quick and easy. The axle pin is secured by the surface on which the box is mounted or the accompanying curved backing plate. This versatile box can be installed in sailboat masts, on boat decks, or any other surface where rope or wire needs to pass through. Key Features: Durable Construction: The body is precision-crafted from marine-grade aluminum for lasting durability. Various Sheave Options: Choose from three different sheave materials and bearing options to suit your specific needs. Versatile Compatibility: Compatible with a wide range of mast sizes and applications. Includes a curved backing plate for mounting on the leading edge of a mast for optimized rope protection and extended rope life. Sheave Options: Acetal Plain Bearing: A lightweight, low-maintenance option suitable for working loads of up to 200kg.