PANZER AR57 ULT UPPER ASSEMBLY 5.7X28MM 16" - ULT 0116 DETAILS: Brand: Panzer Arms Model: AR57 ULT Product Type: Upper Receiver Caliber: 5.7x28mm AR57 16" Full ULT M-LOK Upper, AR57 Mfg, Factory Brand-new. Comes with a 16" light-weight barrel with M-LOK rails. This AR57 Upper Receiver Assembly transforms any AR-15 https://securearmsllc.com/product/the-ideal-conceal-ic380-cell-phone-pistol/