Tamiya item 15428 - JR Mass Damper Square 8x8x32mm Mini 4WD Spare Parts#15428 JR Mass Damper Square - 8x8x32mm - Tamiya Mass dampers have become a staple modification for Mini 4WD machines and these items, which have square shaped cross-sections, will provide racers with another setting option. Not only can they be mounted onto the stays, they may also be cemented onto the chassis as fixed weights. Mass dampers influence pitch and attitude of the mini 4wd car during running. Specs and Features Item 15428 weighs 15.8g. 2x20mm screws, 2mm lock nuts, 2mm nuts, and 2mm washers needed for attachment.