Talboys patented multi-purpose UltraJaws Heavy-Duty Extension Clamps feature an innovative closed yoke construction that minimizes contamination and corrosion of internal components. The unique design enables secure gripping and positioning with added strength and durability. Both single and dual jaw adjustment, jaws open gradually to maximize grip size without binding. Both designs feature precise pressure regulation when gripping glassware surfaces to reduce chance of breakage. UltraJaws Clamps are constructed with extension rods for easy attachment to lab-frames and other apparatus.