Water manometer gauges of heavy duty polythene which is unbreakable.
A screw type zero adjuster is fitted for aligning the water levels with the zero mark on the scale.
Calibrated in inches, water gauge on one side and millibars on the other.
A metal ring is fitted at the top so that the gauges can be hung from a hook.
The 48" size may be rolled up for ease of carrying.
A strap is provided to hold the gauge in the coiled position.