Twist and lock away germs and odours with sangenic tec refill cassettes which lock away germs and odours in advanced multi layer antibacterial film just drop a cassette into the top of the tub and its ready for use in secondsfeaturesnew cassette design fits tommee tippee sangenic tec tubsantibacterial protection film kills 99 of germs on contact100x more effective at odour protection than nappy sackseach refill cassette lasts up to a monthtested against leading supermarket brand nappy