Image 1 of 2 Image 2 of 2 Additel 9240A Differential Pressure Gauge Holder with Built-in Additional Volume for Low Pressure Control $660.00 Add To Cart Added! Differential pressure gauge holder with built-in additional volume for low pressure control. Differential pressure gauge holder with built-in additional volume for low pressure control. You Might Also Like Additel 9816-EU Power Adapter for ADT760 Calibrator $123.00 Additel 9904-916 - Carrying case, space for Additel 916 Generator and two gauges $525.00 Additel 100-NPTF2 Adapter from $65.00 Additel 9258 - Rubber Boot (Blue) for ADT680A gauge $56.00 Additel 9921 Carry Case for ADT835 with Wheels $936.00