Based on this product's specifications, here are some alternatives and similar models
Fan speed controller SilverStone LSB01 — 3-channel manual controller, black, plastic housing, 46×19 mm
Summary description:
SilverStone LSB01 is a compact fan speed controller designed for manual control of up to three fans. The device has a plastic housing in black, measures 46 × 19 mm and weighs 30 g. It provides simple analog adjustment of fan RPM for thermal and acoustic management in PC cases, server racks or small enclosures.