Super long axles + 4 dedicated aluminum extension spacers each. For multiple sets, please comment. 12mm hex hubs can be installed with wheels and nuts up to 6mm-12mm thick (11mm - serrated nuts required). (Thickness 6mm = +16mm wider than 5mm. The wide width also expands to 28mm in proportion to the hub thickness) Since the Tamiya standard hub is 5mm thick, a 1mm-thick spacer is required when installing it as is. When installing large dish wheels + a minimum 6mm thick hub, the threads will protrude as shown in photo 6. (Yokomo and Schumacher wheels are thicker, so the protrusion will be less) Can be used on almost all upright chassis with 1050 or 1150 bearings. For dog bone shafts, not for universal shafts. Can be used on various chassis such as TA01, TA02T, TA04, TA05, TL01, TT02B MS, TT02T, M01, M02, M03, M04, M05, M06, MF01X, FF02, DT02 (Desert Gator only), DF03, WR02, GF01, G6-01, WT01, WT01N, CR01, Manta Ray, Dirt Thrasher, Hotshot, Super Hotshot, etc., but cannot be used on shafts with larger balls than the photo. Please refer to the photo display and check and judge for yourself whether it can be installed. M01-06, FF02, and WT01N idle shafts can also be replaced with this. Super widening allows for stable landings even if you fail a jump on rough roads, and makes it less likely to roll over. You can also use it as a spare when the super long axle with 10mm hex hub, which is no longer available, wears out. It is a regular Tamiya standard expansion method, and no wheel processing like tube nut type wide hubs is required, so it is recommended for those who do not want to widen the axle hole of the wheel. Although the chassis and wheels are new and unused, there may be some scratches due to manufacturing, transportation, and storage, so please understand. The wheels, nuts, dog bone shafts, and calipers in the photos are not included. To keep the price down, we will use recycled paper for simple packaging and ship by non-standard mail. Silent, immediate purchase is possible, and if you don't need it after purchase, we will not contact you except for the shipping notification. I am busy and late, but I will definitely ship within 7 days, so please wait patiently.