Compression spring used to elevate a SAILSetc block into an upright position. Stainless steel. Designed to be used with either of the 61-008 or 61-010 SAILSetc blocks when they are required to stand up from a deck or bulkhead. The spring is added between the block and an eyebolt ref. 143L or 144 or other suitable fastening using Dyneema to attach the two. Allows the block to rotate to align with the load but to remain in place when the load releases so that the sheet is not shortened.