These are SCAR H chest rigs from First Spear. These chest rigs are designed to carry 7.62mm magazines. USGI 5.56mm mags will fit, they however are loose and not very secure. There are sown in pouches to carry up to four (4) 7.62mm mags with a shock cord retention. There is MOLLE webbing to attach additional pouches or accessories. The vest is adjustable for height and waist.