The Vinyl Tubing Y Fitting have barbed ends for securely connecting to standard vinyl and soft PVC tubing.
Plastic Aquarium Connector | Water Pipe Tee Adapter | Pvc Aquarium Connector - 1pcs - Aliexpress
Amazon.com: 2pcs PVC Pipe Y-Type Connector PVC 3 Way Joints Water Pipe Tee Connectors Aquarium Fish Tank Water Supply Pipe Fittings - (Color: White, Size: I.D 40mm) : Pet Supplies
1.26" PVC Pipe Fittings 3 Way Y Shape Water Joint Connectors Adapters 743151941913 | eBay