NOTE: This is an improved seal, the lower end face is raised, has a better sealing effect, it is suitable for P2 gun. The upper and lower end faces of this seal have a special seal design to prevent ISO penetration into the thread gap between SEAL HOUSING and BLOCK. This prevents the ISO crystal from sticking to SEAL HOUSING, making SEAL HOUSING difficult to disassemble and even destroy SEAL HOUSING or BLOCK. The shell of the seal is thickened to extend the life of the seal.