It arrive yesterday and it failed to produce correct result on the very engine I tried it on. Below is an image of the Azono digital tester vs my analog Actron tester. My Actron actually read 110 psi before I bumped it while setting up my camera shot. The Azono only read 17.5 psi. So it is useless for testing the small handheld engines here. Maybe it works on larger engines but definitely won't work 23cc engines.
One thing I did notice is the placement of check valve. It is at the gauge instead at the end of the hose like my Actron tester. Unable to exchange the hoses due different fittings so I couldn't test to see if that was the problem or not but do expect that is one of the problems.
