A double buret clamp is a useful labstand accessory for titration since it can hold 2 burettes, one with acid and the other base; only $6.95.
The height of each buret can be positioned independently so that their respective calibration marks can be aligned. Limited quantity available.
The dual metal burette clamp supports burettes from 10ml (10cc) to 100ml (100cc). They can be attached to support stand rods ~16mm diameter.