Long slide rail system for vehicle seat

A long slide rail system for a vehicle seat, the long slide rail system comprising:

• a lower rail configured to be fixedly installed on a vehicle so as to extend in lengthwise directions therealong;
• an upper rail coupled to the lower rail, the upper rail being configured to enable a seat cushion to be slidably moved along the lower rail;
• a locking module mounted on the upper rail, wherein the upper rail is configured to be slidably moved upon the locking module being unlocked from a locking hole formed in the lower rail;
• a fixing guide coupled to the upper rail, the fixing guide being spaced apart from the locking module in forward-and-rearward directions;
• and
• a moving guide configured to be selectively moved and connected to the fixing guide based on the locking module being locked in the locking hole, the moving guide configured to control, inside the lower rail, a horizontal clearance and a vertical clearance with respect to the upper rail.