Upgrade your HPI car or truck with the HPI Racing 87634 Reduction Gear Box Set. This set includes a 1:7.4 ratio for increased torque and power. The black gear box is compatible with electric, nitro, and glow fuel types for versatile use. Designed for 1:6, 1:8, and 1:10 scales, this HPI part is made in Taiwan with durable materials for long-lasting performance. Suitable for ages 8 and up, this gear box set is perfect for RC enthusiasts looking to enhance their vehicle's capabilities.