Interline companies sell to the same kinds of professional contractors and end users that PHCP, HVAC and PVF distributors do. Additional competition is coming from Amazon Business, the replacement for Amazon Supply (but no PVF), Alibaba (where some products are sold in small quantities) and Grainger. Less competition is coming from MSC Industrial Supply (a small selection) and McMaster-Carr (a small selection of plumbing, no HVAC equipment or pipe). Not threatening are HD Supply, Kaman Industrial Technologies and WESCO.