A citronella spray refill that works with PetSafe® Elite Little Dog Spray Bark Control Collar. Citronella can be a more effective deterrent for some dogs than the unscented spray. To properly refill collar the unit must be turned off. Make sure the spray can is upright while you firmly press the nozzle down into the refill port. Hold for 15 seconds and remove. If spray leaks out during refill, you may need to press harder to complete the seal.