Bernard Style Gas Diffuser Tip Holderfor 250, 300, 400 & 500 amp Bernard style Mig Guns 5 Pack.Select from the list: 4235 Use with (Long Tips for 250/300 amp guns) 4335 Use with (Short Tips for 250/300 amp guns) 4435 Use with (Short Tips for 400/500 amp guns) 4635 Use with (Long Tips for 400/500 amp guns)Gas Diffuser, Tip Holder, Head, Bernard Style for 250, 300, 400 & 500 amp Bernard style Mig welding guns.Bernard CenterFire Consumable Users: Reduce your operating cost by switching back to the original Bernard style Elliptical "twist" contact tips. Replace your center-fire tips, nozzles and tip holders with efficient - lower cost standard parts.