The first shatter-proof heater thanks to the peculiar glass tube.
Maximum security: THEO is shock resistant thanks to the PTC heating element and the shatterproof glass tube.
Free positioning in the aquarium: vertical, horizontal and completely submerged.
Self-limiting: the patented PTC heating system guarantees operation in complete security because in case of dry running there is no danger for damage.
The 25W, 50W, 100W & 150W models are the smallest available on the market, they measure only 17.8 cm e 22.6 cm (7 in e 8.9 in ).

#343025 - Hydor THEO 25 Watt Heater 7" ~ $19.99 
#343050 - Hydor THEO 50 Watt Heater 7" ~ $20.49 
#343100 - Hydor THEO 100 Watt Heater 8.9" ~ $20.99 
#343211 - Hydor THEO 150 Watt Heater 8.9" ~ $21.99 
#343200 - Hydor THEO 200 Watt Heater 12" ~ $23.49 
#343300 - Hydor THEO 300 Watt Heater 15.5" ~ $23.99 
#343400 - Hydor THEO 400 Watt Heater 15.5" ~ $30.99 
MINI HEATERS
#343191 - Hydor 7 watt Mini Heater ~ $12.99 
#104747 - Hydor 15 watt Mini Heater - adds 5-7 degrees to 5-10 gallon aquariums ~ $15.99 