Time to delivery: 2 weeks, shocks oil filled, product seems of good quality. Probable a more dense oil can be better to improve rebound speed but in general a good upgrade vs original shocks

The shocks work quiet well to compare with original springs on Q901. The difference is absolutely sensible. The spring is stronger than original and diameter of shock is a bit bigger than stock one. The value for price is moderate cause the only metal parts are spring and shock caps. There are bunch of shocks out there with full metal body though but Xinlehong family are forced to buy the only available shocks upgrade. Personally do not like appierence because of plastic part and low quality red color of springs. Notice the photos I attached, the spring color came off in different parts before installation. All in all, the first and the most important upgrade for your RC. Recommended without doubt.