The Zero In Flea Killer Refill Pack is for use with the Zero In Flea Killer Trap.
 
Safe and effective household treatment for flea problems without using poison sprays
Each bulb is 7 watt and rated for 1000 hours of continuous use.
The refill discs should be changed every 2 - 4 weeks.
Poison and chemical-free, odourless refills for the control of flea infestations in the home