The Volcano drain is the most versatile drain on the market with its ability to fit in 4″, 3″, 2″, & 1.5″ drain openings. Simply cut a 4″ hole in a sump cover & install the Volcano Drain for an airtight seal that doubles as an access port. The recessed lip design helps to collect multiple drain lines & the grill on top can be removed for cleaning as needed. Designed by radon professionals, the Volcano Drain is the most versatile floor drain on the market!