Even tiny trucks need a little help at times, and the MSA-1E line gets just that by lowering it's center of gravity and adjusting it's weight-bias to aid crawling. Each of the 4 hex's in the set weighs in at 2g and can be used to weight just the front axle to improve weight bias, or all four added to weight both axles, and offer the full 8g. Features Brass Weight Wheels Hex Set for MSA-1E Trucks 4 Piece