Part# 612T-037B-2. Piston Wear Rings. SEAL INFORMATION: MATERIAL: NYLON, TEMP: -40? to +230?F, SPEED: 1.5 FT/SEC. PRODUCT DETAILS: Nom. ID: 3/8, Nom. OD: 1/8, Nom. Ht: 2, Style: 614 NYLON ROD BEARINGS, Brand: Hercules.