Replaces the factory foot of your lens, lowering the center of gravity for optimal balance Adds a built in double dovetail for Arca Swiss compatibility For Nikon Z 400 f/2.8 TC, 600 f/4 VR S-line, and 800 f/6.3 VR S-line Lenses Anodized 6061 Aluminum, stainless steel fasteners Made in USA. Assembled in Charlottesville, Virginia About the AP-502 Replacement Lens Foot The AP-502 replaces the stock foot on Nikon Lenses (See list below, Image of compatibility chart, or our site). The AP-502 is precision machined to slide right into an Arca-Swiss style quick-release clamp. It also has 1/4" and 3/8" tapped holes for mounting to non-quick-release tripod heads and monopods. All replacement feet feature the same dual safety stops and flash bracket compatibility as our lens plates. For use on the following Lenses Nikon 400 f/2.8 TC Z VR S-line, 600 f/4 TC Z VR S-line, and 800 f/6.3 Z VR S-line Lenses Includes AP-502 Arca-Swiss Style replacement lens foot (Qty 1) Mounting Screw – M4 x 14mm Socket Head Cap Screw (Qty 4) Safety Stop Screws - M3 x 6mm Socket Head Cap Screw (Qty 2) Hex Key – 3mm T-Handle (Qty 1)Hex Key – 2.5mm (Qty 1) Not compatible with most Manfrotto or Gitzo clamps