29 mm Zircon Triple Block — Becket

Harken 29 mm Zircon Triple Block — Becket

The Harken Zircon series represents some of the most efficient sailing blocks available, and the 29 mm Triple Block with Becket extends this performance to smaller control line applications requiring multi-part purchases. The Zircon line now spans eighteen models following the addition of six new 29 mm sheave diameter variants, making high-performance block technology accessible across a wider range of dinghy and small boat rigging setups.

At the heart of the Zircon's performance are industrial ceramic ball bearings mounted in a caged race. The cages keep the bearings separated so they do not bunch, touch, or impede one another, resulting in the lowest possible friction and the most efficient block Harken has produced at this scale. This translates to immediate, precise response whenever load changes — whether easing a deep-rigged Cunningham or moving a jib lead forward to open up power through choppy conditions.

The triple-sheave configuration with integrated becket allows multi-part purchase systems to be rigged in a compact, lightweight package. At only 32.5 g and 54 mm in length, this block adds minimal weight and windage while delivering a 240 kg (525 lb) maximum working load and a 720 kg (1575 lb) breaking load. Maximum line diameter is 6 mm (1/4 in), covering the typical control line sizes found on performance dinghies and small keelboats.

The block is backed by a 5-year Harken warranty, reflecting the brand's confidence in Zircon's durability and long-term performance even under repeated high-cycle use.

Key Features

• Industrial ceramic ball bearings in caged race for maximum efficiency and immediate response
• Triple-sheave design with becket for multi-part purchase systems
• 29 mm sheave diameter; 54 mm overall length
• Lightweight at 32.5 g (1.15 oz)
• Maximum working load: 240 kg (525 lb)
• Breaking load: 720 kg (1575 lb)
• Accepts lines up to 6 mm (1/4 in) diameter
• 5-year Harken warranty