ABOUT THE MAINSTREAM COLLECTION — Give your bathroom a fresh update with the Mainstream shower options. The collection includes a 32-inch shower door, coordinating wall system and shower base, each sold separately. Choose only the pieces you need or plan a complete shower makeover that’s easy and affordable. The Mainstream Shower Base from American Standard gives the shower a fresh, new look. Made of high-gloss acrylic, it features a low, 3.25” threshold for safety and ease when entering and exiting. Add the coordinating Mainstream shower door and wall surround, each sold separately, for a complete update.