1″ Outside Diameter Freeland Plastic Front Sight Apertures for Freeland 1″ Sight.Color: BlueSelect Aperture Hole Size
| US Size | Metric Size |
| .060 | 1.6 |
| .070 | 1.8 |
| .080 | 2.0 |
| .090 | 2.2 |
| .095 | 2.4 |
| .100 | 2.5 |
| .105 | 2.6 |
| .110 | 2.8 |
| .115 | 2.9 |
| .120 | 3.1 |
| .125 | 3.2 |
| .130 | 3.3 |
| .135 | 3.4 |
| .140 | 3.6 |
| .145 | 3.7 |
| .150 | 3.8 |
