FREE UPGRADE...Get TK PLUS for the price of TK9A!. Compare to TK9A, the Acugauge TK PLUS backflow test kit is a 3-needle-valve test kit for testing all makes, models and sizes backflow preventer assemblies, including irrigation, domestic, isolation, containment and fire. The Acugauge TK PLUS backflow tester ships fully assembled and with everything needed to start testing right away: hoses and10-pc testcock adapters. The Acugauge TK PLUS backflow gauge also comes with a calibration certificate valid for one year from date of shipment. The Acugauge TK PLUS backflow differential pressure gauge is an upgrade to TK9A: the PLUS uses 3 instrument-grade needle valves, whereas TK9A uses 1 needle valve and 2 ball valves. Both use the same operating procedure. Why needle valves? Because they are more durable and accurate than conventional ball valves due to their orifices, not present in ball valves. Main Features: 3-Needle Valve configuration - high, low and bypass 4.5" Differential Pressure Gauge; scale: 0 -15 PSID Extra Line Pressure Gauge for conveniently reading system pressure, now required by most water purveyors; scale: 0-160 PSI Full set of Test Cock Adapters: (3) 1/8" , (3) 1/4" , (3) 1/8" (total of 9) Full set of Backflow Test Hoses: (3) 36" color-coded (red, blue and yellow) with knurled swivel quick couplers for easy on and off without tools Made for testing RPZ, DC, PVB, SPVB, DCDA and RPDA Ships fully assembled with calibration certificate valid for 1 year - start testing right away Capable of performing all test procedures recommended by ASSE, AWWA, CSA, FCCC and HR-USC. TRY IT FREE FOR 30 DAYS. This might change your mind. All Acugauge products are protected by our 30-DAY MONEY BACK GUARANTEE. If you don't love it, return it - no sweat. We'll even pay your return shipping!