Probe SRS Series Pistons for the 5.7 and 6.1L Late Model Hemi Based Engines are manufactured on advanced 2618-t6 forgings; featuring forged side reliefs with internal and external bracing. Most feature double spiral locks (or wire locks in some applications), forced pin oilers with oil distribution grooves, and lock removal indentations. They also feature gas accumulator grooves in the second land and double forced pin oilers with oil distribution grooves, as well as optional gas ports. Locks, wrist pins, and lock removal indents are included.