![Ronstan Series 40 All Purpose Block - Single Upright Lead [RF41171]](https://cdn11.bigcommerce.com/s-e6ht4dde3g/images/stencil/1280x1280/products/46672/63096/70602XL__80173.1745529462.jpg?c=2 "Ronstan Series 40 All Purpose Block - Single Upright Lead [RF41171]")
Series 40 All Purpose Block - Single Upright Lead
Lead blocks are a low profile solution for leading halyards or other rig sail controls back to cleats or jammers. Ideal for high load applications. Wear resistant sheave material, in lightweight, self lubricating polymer, is suitable for use with rope or wire.
Applications:
- Typically used for halyards at the mast base.
Materials:
- UV stabilised acetal sheave
- Grade 316 stainless steel load housing
![Ronstan Series 40 Ball Bearing Block - Single Upright Lead [RF40171]](https://cdn11.bigcommerce.com/s-e6ht4dde3g/images/stencil/500x659/products/17896/21108/70615XL__90808.1601532775.jpg?c=2 "Ronstan Series 40 Ball Bearing Block - Single Upright Lead [RF40171]")
![Ronstan Series 40 All Purpose Block - Single Cheek [RF41811]](https://cdn11.bigcommerce.com/s-e6ht4dde3g/images/stencil/500x659/products/46673/63097/70607XL__58024.1745529465.jpg?c=2 "Ronstan Series 40 All Purpose Block - Single Cheek [RF41811]")
![Ronstan Series 40 All Purpose Block - Single - Universal Head [RF41100]](https://cdn11.bigcommerce.com/s-e6ht4dde3g/images/stencil/500x659/products/11254/13455/55201XL__67438.1601520266.jpg?c=2 "Ronstan Series 40 All Purpose Block - Single - Universal Head [RF41100]")