Ronstan S40 AP Block,Single Cheek (RF41151)

All purpose (AP) blocks are a great all around solution. Self-lubricating Acetal polymer sheaves running on polished stainless steel races perform equally well with dynamic loads and high static loads. For durability and a long service life, these blocks are the right choice for sheets, halyards and control line applications for cruising and racing.Can be mounted on masts and booms using the curved surface adapter. Can be stacked to create a double version, but no more than 60% of the rated working load should be applied to the upper sheave.