Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| Model | Frame | Years Mfg'd | Caliber(s) | Production | Barrel | Notes |
| --- | --- | --- | --- | --- | --- | --- |
| Remington-Beals Army Model Revolver | Large | 1861-1862 | .44 | 1,900 (estimated) | 8 inch octagon |  |
| Remington-Beals Navy Model Revolver | Medium | 1861-1862 | .36 | 14,500 (estimated) | 7 1/2 inch octagon |  |
| 1861 Army Revolver (Old Model Army) | Large | 1862 | .44 | 6,000 (estimated) | 8 inch octagon |  |
| 1861 Navy Revolver | Medium | 1862 | .36 | 7,000 (estimated) | 7 3/8 inch octagon |  |
| New Model Army Revolver | Large | 1863-1875 | .44 | 122,000 (approximately) | 8 inch octagon | Used for factory conversions in .46 RF & .44 Remington |
| New Model Navy Revolver | Medium | 1863-1875 | .36 | 28,000 (approximately) | 7 3/8 inch octagon | Used for factory and U.S. Navy conversions to .38 RF & CF |
| New Model Single Action Belt Revolver | Large | 1863-1875 | .36 percussion and .38 CF | 2,500 - 3,000 (estimated) | 6 1/2 inch octagon | Factory conversion production started in 1873 |
| Remington-Rider Double Action New Model Belt Revolver | Large | 1863-1873 | .36 percussion and .38 CF | 3,000 - 5,000 (estimated) | 6 1/2 inch octagon | 1863-1865 available with fluted cylinder, conversions had two-piece cylinder |
| New Model Police Revolver | Medium | 1865-1873 | .36 percussion and .38 RF | 25,000 (estimated) | 3 1/2, 4 1/2, 5 1/2, 6 1/2 inch octagon | Conversions all believed to be rimfire only |
| New Model Pocket Revolver | Medium | 1865-1873 | .31 percussion and .32 CF | 25,000 (estimated) | 3, 3 1/2, 4, 4 1/2 | Majority produced as conversions or cartridge |
Question:
which model is the only model to have the lowest caliber?
Answer:
New Model Pocket Revolver