Amazon.com: FangKingNo10pcs 3/4" White PVC Pipe Coupling Adapter Pipe Fittings (Slip to Slip) Schedule 40 Easy to Install,and High Tensile for Home or Industrial Use (1 Pack of 10pcs) (0.75 Inch) :
Plastic Pipe Coupling, PVC, 3/4 inch x 3/4 inch, Female NPT Thread x Female
Zoro Select PVC Coupling, Socket x Socket, 1 in x 3/4 in Pipe Size 429131 | Zoro