This is the optional Extended Battery Hold Down Set for the Traxxas E-Maxx Series. FEATURES: Composite nylon construction, black in color Install one way and you can secure battery packs up to 21mm in height flip it over and install for battery packs up to 28mm in height Two sets of adhesive backed foam blocks help keep the batteries in place (thick blocks for 21mm use and thin blocks for 28mm use) INCLUDES: Two Battery Hold Down Straps Two 21.3mm Thick Foam Pads Two 6.4mm Thick Foam Pads One Installation Instruction Sheet REQUIRES: Installation SPECS: Length: 7.5" (190mm) kpm02/27/2008 ir/jxs