Designed for the Nikon AF-S NIKKOR 500mm f/5.6E PF ED VR, the AP-500 Quick Release Replacement Foot from Wimberley is an anodized 6061 aluminum foot that is Arca-type compatible for use with most clamps and heads on the market. By replacing the original factory foot, the AP-500 adds rigidness and stability and reduces flex and vibration while mounted ahead. Additionally, a double dovetail allows accessories to attach to the bottom or the top of the foot. The lower profile of the plate provides better balance when mounted ahead as well. If you're going to use the optional safety stop screws, Wimberley recommends using a clamp with channels, which allow the screws on the foot to slide back and forth.