Bow Shackle - Rounded shackle with a threaded pin that is used in applications which require attaching multiple items to one shackle.
D Shackle - Standard shackle with a threaded pin designed to attach one item to a piece of hardware and with the load usually perpendicular to the attachment point.
Deep D Shackle - Extra long standard shackle which provides additional clearance.
Halyard Shackles - Either a stamped or forged shackle with a captive pin used for halyards. Dimensions stated are Width x Length.
Twisted Shackle - Specialty shackle which can be used when a block or lead orientation needs to be changed 90 degrees from the attachment point.