The Wavin below ground drainage system is available in 110mm and 160mm pipe and fittings. PVC-U underground gravity drains and sewer fittings are suitable for use in conjunction with WavSpec SN4 or SN8 pipe and Wavin chambers for domestic and public sewerage and drainage. The system features RootSeal technology, which helps to repel tree roots and reduce potential damage, upheaval, and costs. The sewer fitting stop end is 6 inches in size.