... called sucker rod centralizers Material: Nylon Size: 3/4, 7/8 for 2-7/8 tubing Specifications1. sucker rod guide, sucker rod guides ... sulfide and carbon dioxide solutions; available for 2-3⁄8, 2-7⁄8, and 3-1⁄2 inch tubing.Rubber — a slotted, hammer-on, spring ... 250 degrees F) and low gas production; available for 2-3⁄8 and 2-7⁄8 inch tubing. sucker rod guide,Standard Rod Guides