3 piece kits consists of:1 x DPG-3016: Precision CNC machined nodal slide.Compatible with all Arca-swiss style quick-release plates. Accurately find nodal point for panoramic photography.Double Dovetail allows you to mount the rail to an arca clampand combine with the Subtend Clamp for incredible versatility. Width: 39mm.Length: 300mm.Height: 16mm.Weight: 254g.Mounting holes: 4 x 1/4"-20, 1 x 3/8"-16.1. Precision machined from solid aircraft-grade aluminum.2. Hard -anodized finish, durable and resists scratches.3. Includes 4 metal stops.4. Easy-recognized laser-engraved scale on both sides of the rail to adjustthe nodal point conveniently and accurately.5. Safety stop screws included.Includes all the screws and tools pictured.2 X Subtend Clamp DDT-53, Under and over independent Arca clamps.Use it with 2 long plates or rails for precise dual control. Length: 54mm.Width (inc handles): 130mm. Height: 22mm. Weight: 158g.All metal construction.Metal knobs with no rubber or plastic. Compatible with all Arca Swiss plates.