This Remington manufactured fourth variation slide with operating handle plunger & spring is for the model 11-48 semi-auto shotgun in 12 gauge and having the fourth variation breech bolt with carrier cut on the underside. The overall condition is very good with light wear. (file photo)

Note: Remington model 11-48 semi-auto shotguns with the following gauge and serial numbers have been observed with this part:

12 Gauge: 5184301