Replacement Dell Ozone Chip for Dell Ozone unit, instruction for fitting on Dell Ozone site. Only undertake if you know what you are doing and have checked out the Dell Ozone site and instructions. Electricals on spa must conform , be correct and protected by a 30milli amp RCD , disconect if undertaking any work, any sales are made on the basis you are competant. This product is on a supply only basis and any instruction or advice must be gleened from elsewhere and you must satify yourself you know what you are buying and what you are doing, there is plenty of advice out there, but you usually have to pay for it, Research on the internet is free and the Dell ozone site has it all. We are unable to accept any retruns on Ozone chips that we supply as a genuine part at the lowest price in Europe.