Piston with ring for Ramset Cobra and other DX350 clone tools. Recommended replacement part. Ramset part #SC301200A Inspect old piston for chips and wear, replace accordingly. DOES NOT FIT THE RAMSET COBRA PLUS! Please note, some of the big box stores have offered a Cobra Plus tool with power adjustment. All though we are a full line Ramset dealer, this tool was offered exclusively through the big box stores, please contact them for parts.