Bernard Centerfire MIG Nozzle Insulator Cap (4523R) Bernard Sale! from 1040 /per Qty. Add to Cart This item is currently on backorder but you can still purchase it now and we'll ship as soon as more become available. Bernard™ Centerfire™ MIG Nozzle Insulator Cap - 4523RPackage of 1 - Genuine Bernard™ Centerfire™ 4523R small nozzle insulator cap. Works with Bernard Q 150 MIG guns. SKU:BER 4523R