Small size , portable , you can carry it with you wherever you go for Ideal for household and laboratory testing applications , including drinking water , swimming pool , pond , aquariums With data hold , ℃ / °F switchable function , built-in 3x1.5V button battery Can measure ORP , , and Temp value with high at the same for time There are 2 types , with & without backlight , choose based on your needs, Manufacturer: Watreketal