This is Yokomo YD-2 SLF Big Bore Shock 1.4mm x 4 holes Piston 4 pcs Black. Variations will be added to the piston for the YD-2 big bore shock. By setting the hole diameter to 1.4 mm, it can be operated flexibly even when the grip is low. By making the suspension easier to move, it enhances traction when cornering. It is a drift category where oil with a fairly low viscosity is often used, but by widening the piston hole, it is easy to operate even with slightly hard oil (about # 200 to # 300), delaying the penetration of silicone oil into O-rings etc. , It will be possible to maintain good condition for a long time.