Having the right spares on-hand when out diving can make or break a dive. Don't let a broken rail on your Hollis SMS 100 Side-Mount BCD ruin a day-of-diving, always carry a spare. The Hollis Gear Rail Kits are manufactured from corrosion resistant stainless-steel and come complete with mounting hardware. These Hollis Rail Kits are easy to install and make a great save-a-dive-kit item.