GBE VELOCITY STACK FOR STOCK FILTER BAJAGBE's innovative new billet velocity stack for the HPI Baja 5b/5T is much better than the stock plastic setup for the following reasons. 1. As it is made of billet aluminum, it will not warp 2. Filter has been moved up slightly, so the filter is easier to remove. Also, installation of redneck or outerwears prefilters is made much, much easier with the extra space 3. Air volume is increased, so more air is accessible to the engine at initial throttle. Fits HPI Baja 5B/5T with STOCK FILTER ONLY. Will not work with aftermarket filters.