Twin Sheave Block and Tackle 0.43-0.5Inch 100-200Ft Twin Sheave Block with Braid Rope 30-35KN 6600-7705LBS Double Pulley Rigging (1/2" x 200')

The diameter of the roller is 56mm, the height of the whole pulley is 151mm, and the width is 82mm.

It will not lock when carrying a load.

While the product description doesn't mention arborist work specifically, customers appreciate its versatility and strength. One review mentions using it for tree work, suggesting it is suitable for arborist tasks.

While the product description doesn't mention rock climbing specifically, customers use it for mountain rescue and climbing. The rope has a 7,700 lb breaking strength and is 200 ft long, which could make it suitable for rock climbing applications.

I did not find any information about replacement parts in the product description or customer reviews.