Ronstan's Core Blocks have a 2-stage bearing system which provides excellent performance across the full working load range. Under light and moderate loads, ball bearings minimize friction and also act as side-load/thrust bearings when the lead isn't fair. At loads that would deform the ball bearings, a solid bushing takes over, maintaining low friction performance. Use these blocks for sheets, halyards and control line applications for either cruising and racing.
• Versatile - easily handles high dynamic loads, as well as heavy static loads
• Shackle head lockable at 0 or 90 degrees
• Acetal (grooved for wire) sheave options
• Removable 8mm (5/16”) threaded pin at head
• Aluminum alloy cheek plates shaped for maximum strength, light weight, ease of freshwater rinsing, minimal chafe
• Beckets have removable pins to allow fitting of pre-spliced lines
• On non-becket models, the central hub hole can be used as a becket take-off or tie-up point