They have never been used. A bit dusty from being kept in storage. The Inspection Chambers Base Drainage Man Hole is a 110mm OSMA Drain 460mm deep that provides efficient groundwater drainage. Manufactured by OSMA, this product is designed for use in various building materials and supplies for business, office, and industrial settings. With its durable construction and reliable performance, this inspection chamber base is a key component in ensuring proper drainage and preventing water damage in construction projects.