Works with matrix tables having 20 mm diameter holes (e.g. Festool MFT). Ideal for work surfaces 19 to 25 mm thick. Set includes: 1X cylindrical screw M8 x 35 mm; 1X lock pin 20 mm OD x 17 mm long; 1X knurled knob with M8 thread. Use on BESSEY Auto Adjust toggle clamps with horizontal base plate: Horizontal toggle clamp STC-HH50 / -HH70; Push/pull clamp STC-IHH25; Vertical toggle clamp STC-VH50 STC-SET-T20 is a low cost optional accessory - clamps not included.