These all-metric M6 threaded T-slot bolts have 18 x 12mm heads. They are a direct fit into UJK Technology T-Track in the UJK Track and Stop Kit, the UJK Universal T-Track as well as the T-Track on the UJK Router Fence and many similar sized 1/2" T-tracks. The M6 thread is available in 3 lengths: 25mm, 50mm and 75mm. The metric thread (rather than the usual UNC thread) opens up a wider range of options especially with other easily available metric threaded fittings. Supplied in packs of 10.