RetroArms Cylinders are CNC out of high quality superior stainless steel. Super smooth on the inside so your piston O rings stay healthy and don’t get cut up from unwanted burs.
CNC Stainless Steel Cylinder Port Chart
| Cylinder Port Type | Inner Barrel Length |
| Type A | 130 - 239mm |
| Type B | 240 - 289mm |
| Type C | 290 - 369mm |
| Type D | 370 - 469mm |
| Type E | 470 - 650mm |