Differential pressure gage, range 0-0.5inwc, 1/8in male NPT connection, Dwyer Instruments, Mfr#: 2-5000-0-NPT$72.00+
Differential Pressure Piston Type Gauge, Al 2520PSI16Bar, Dwyer Instruments, Mfr#: PTGD-AA04A$340.99+
Differential pressure gage, range 0-50 mm w.c., for vertical scale position only., Dwyer Instruments, Mfr#: 4000-50MM$1,094.99+