Coupling for Spee-D channel drains. NDS Spee-D channel drains are a proven alternative to traditional concrete drains with UV inhibitors are used to prevent fading and cracking from the sun, chemical-resistant, rustproof and maintenance-free, lightweight and easy to install. The most popular applications for this channel include swimming pools, spa and patios.Coupling for Spee-D channel drain,Can be solvent-welded,Flanges on the bottom provide for easy, secure installation