The patent-pending BigStep piston perfectly fits the VST ridgeless filter baskets (58.7mm diameter or larger), giving you full compaction with almost no residual grounds on the side-walls. That means you're compacting your puck fully and evenly across the entire surface, which greatly helps in reducing channeling and uneven extractions. The tapered step in the base design reduces suction while removing the tamper, so dislodged or fractured pucks are much less of an issue. The 58.55mm BigStep base is made from 440 grade stainless steel. The tamper is an ergonomic unit with a comfortable curve running throughout all its components. It starts with a handle made of anodized aluminium. Between the base and the handle there's also the option to add one of the three height adjustment spacers supplied with each tamper.