I have not compared them to a calibrated thermometer but all 4 read within 0.1F and installed alongside half a dozen other digital thermometers they read the same. I'd say that's enough to call them correct. Incredibly cheap, but works great!
capetsma Reptile Thermometer: Accurate and Easy-to-Read Digital Hygrometer for Reptile Terrariums - Temperature and Humidity Monitor in Acrylic and Glass Terrariums (1 Pack)
8 Review
Lush Live Aquarium Plants: Pest & Algae Free Greenpro Tissue Cup With Lagenandra Meeboldii, Anubias, Cryptocoryne, Bucephalandra & Piptospatha Ridleyi
17 Review
π‘οΈ Zacro LCD Digital Aquarium Thermometer: Accurate Fish Tank & Terrarium Water Temperature Monitoring
8 Review
π‘οΈ Qooltek Digital LCD Thermometer Gauge with Probe for Vehicle Reptile Terrarium Fish Tank Refrigerator - Fahrenheit Aquarium Temperature Sensor
8 Review
Jasonwell Magnetic Aquarium Fish Tank Glass Algae Cleaner - Floating Brush (L Size)
37 Review
π U-BCOO Aquarium Gravel Cleaner Fish Tank: Manual Siphon for Efficient Filter Gravel Cleaning and Water Change in Tanks
22 Review
Steam cleaner Deerma Deerma DEM-ZQ610 EU, white/red
68 Review
𧲠Efficient Magnetic Fish Tank Cleaner: KEDSUM Floating Clean Brush with Handle Design
34 Review