With transverse and longitudinal vials.
Used as level and slope meter to measure the angle of two separate surfaces
Aluminum frame.
Magnetic bottom.
The sea level is permanently set inside the chip, zero setting is not needed when batteries are replaced.
Buttons: ON/OFF, absolute and incremental measurement, keep the reading, buzzer alarm(not for 4910-400), unit (mm/m, %, in/ft), conversion(not for 4910-400), backlight
The display flips over when the bottom faces up

Standard Abrasives 709700, A/O Straight Cartridge Roll, 1/4 in x 1-1/2 in x 1/8 in 320, 7100080013 
