The SteelSeries Rival 300 was one of the defining ergonomic gaming mice of the mid-2010s at 130 grams wired with the PMW3310 sensor. Its large, comfortable right-handed shape made it a popular choice among professional players before the ultralight revolution changed expectations around weight. The Rival 300 featured rubber side grips and a split-trigger button design that became a SteelSeries trademark. Professional CS:GO players including several from the Nordic scene used the Rival 300 during major tournaments. Though its weight makes it feel like a relic by modern standards, the Rival 300 represented the pinnacle of traditional gaming mouse design before the industry pivoted to ultralight.