The Headboard Shackle has a captive pin with a self-locking feature so that the pin will not back out. The pin is integral to the shackle body, it is not removable and will not fall out when open. The Headboard Shackle is made from grade 316 stainless steel for maximum corrosion resistance and durability. Available in sizes ranging from 1/4" to 1/2", it is ideal for marine applications because the pin can’t be accidentally dropped in the water.