The Big Bores are stylish with Chrome and Black anodizing and a large P-L logo engraved into the shock cap. Pro-Line also engineered an updated dual-rate spring design made from a single spring that saves space and has incredible scale looks and performance. Optional softer and firmer dual-rate springs are available in the Big Bore Scaler Shock Spring Assortment (6343-02). The lower spring perch is captured, so you always know it will stay where it belongs. From the top mounting hole to the bottom mounting hole, these Big Bore Scaler Shocks measure out to be 90mm at full extended length and collapse down to about 64mm (when the rubber bump stop is removed) and they include extra 5mm longer Shock Ends to increase the shock length. The Big Bores come mostly pre-built (just add oil) and are designed to fit many popular crawler vehicles.