Holdfast 

Cast Ductile Iron, hot oil finish. Overall shaft length is 13" (33.0 cm), overall length of reach is 7.25" (18.4 cm), weight is 2.15 lbs. (0.975 kg). Low profile, flexible enough to grip the work firmly, but easily loosened with a hammer. Fits a 3/4" diameter hole in a 2 3/4" to 4" thick benchtop (if your benchtop is thicker, you may need to relieve the bottom third of the hole to 1" diameter). 

Sold in singles.