The new connectors for the exhaust air to better control the odours. In conjunction with ONA blocks, for the neutralization of undesirable odors in the exhaust air duct. Suitable for all ONA blocks. Open the lid and place the ONA block inside. The exhaust air controls the rest, so there are no unwanted odors. When the block is used up, simply open the lid again, take out the remains of the block, put in a new block and close the lid again.