The Arcadia Reptile Ultraseal lamp holders offer both keeper and animal total security against dangerous water ingress. To comply with the new waterproof lighting regulations we have designed and made this system to be IP67 or waterproof. This does however mean that the lamp holders must be tight. To enable the safe and easy fitting of lamps the following advice is given:   Unscrew the lamp rings from the lamp holders. Use a very small amount of Vaseline on the rubber seal on the inside of the sealing ring to moisturise the rubber seal. Wipe away and overspill from the lamp holder and lamp. Slide the lamp ring over the lamp and carefully line up the pins on the lamp with the two holes inside of the lamp holder and push gently. The lamp should seat into the lamp holder with a slight click. Do not turn the lamp as the pins will sheer off. Slide the lamp ring back down towards the lamp holder and holding the lamp tight with one hand screw up the lamp ring until gently seated with the other. T5 lamp run hotter than T8 lamps and the rubber seal around the lamp sealing ring may stick to the lamp or degrade over time, these rings can be easily replaced with product code AB5R.