Check the listing for details. Hayward Sense and Dispense HL-CHEM Chemistry Kit. Condition: Open box. Listed at 750.00 USD. The Hayward Sense and Dispense HL-CHEM Chemistry Kit is a convenient pool water testing and treatment product suitable for all water types. Designed by the brand Hayward, this kit includes a sense and dispense feature for easy monitoring and adjusting of salt levels in swimming pools. Perfect for maintaining clean and healthy water in your pool or spa, this chemistry kit is a must-have for any pool owner looking to ensure optimal water conditions.The Hayward Sense and Dispense HL-CHEM Chemistry Kit is a convenient pool water testing and treatment product suitable for all water types. Designed by the brand Hayward, this kit includes a sense and dispense feature for easy monitoring and adjusting of salt levels in swimming pools. Perfect for maintaining clean and healthy water in your pool or spa, this chemistry kit is a must-have for any pool owner looking to ensure optimal water conditions.