This Gibraltar lightweight, compact throne has a 13" round, cushioned vinyl top, with high-quality foam for maximum comfort. The base is single-braced with a cast height-adjust collar and nylon bushing. The height-adjust support stem is knurled and allows you to fine-tune to your exact height. The knurled support stem is equipped with a memory lock that uses a wing nut tension adjustment. Features 13" vinyl round-top throne Single-braced tripod base Compact and lightweight Cast height-adjust collar with nylon bushing Knurled adjustable-height stem Memory lock with wing