Super Angle Lock Precision Swivel Base Milling Machine Vises With Swivel Base Removable hinged handle for fast locking Provides better clamping pressure Item Jaw Width (A) Jaw Opening (B) Jaw Depth (C) Length (L) Width (W) Height (H) Weight FA20-4203 3" 3.543" 0.945" 10.433" 4.528" 3.740" 19 lbs FA20-4204 4" 5.511" 1.259" 13.582" 8.858" 4.724" 39 lbs FA20-4206 6" 6.299" 1.771" 17.322" 10.944" 6.023" 83 lbs The accessory is designed for precise vise positioning and is optional, depending on the user's setup requirements. When in use, the groove on the vise base aligns with the T-slot or locating groove on the machine table. This alignment enhances stability and clamping strength by securing the vise firmly to the table. Use as needed based on your machine configuration. Reference the attached images for visual guidance.