The TW16A-STC is just one of the many accessories available for the BESSEY welding table clamps. This versatile adapter makes it possible to use many of the BESSEY STC series toggle clamps on your 16 mm matrix table. Many other accessories are available, such as V-blocks, variable risers and an assortment of adapters that allow use of the TW16 & TWV16 series clamps on woodworking benches with 3/4 inch, 20 mm, 1 inch & 30 mm bench dog holes. BESSEY. Simply better.