Heater Sensor assembly comes complete with clear plastic housing and o-ring to suit SV Series Heater Tubes on SV2/SV3/SV4. We highly recommend this product be installed by a qualified electrician or spa pool technician. Pool & Spa Superstore will not be liable for incorrect installation, damage, or injury caused by an unqualified person installing this part. We’re a Kiwi owned and operated company with over 20 years combined experience in the industry. We’re committed to only selling leading brands at the best prices alongside expert advice. If you have a question about a product, just ask us and one of our experts will provide an answer. We are the exclusive Spa parts & accessories provider for Alpine Spas - NZ’s largest Spa Pool retailer.