Do you have a nut or bolt that is at an long depth and you need a straight extension bar? Make sure to add this set of extension bars to your tool set. With these extensions you can get into those further reaches quickly and easily. All four extensions are 3/8 inch drive. Constructed form heat treated steel they will last for years to come. Most home owners and people that work on their own cars or motorcycles will make sure to have a set in their tool selection. Make sure to add a set to your tools.