The Blackburn Mammoth 2 Stage pump features a massive barrel designed specifically for today's bigger mountain bike tires. It has dual mode internals with a high pressure and high volume mode easily changed with a switch on the end of the pump. Use the low mode for a completely flat tire. Switching the mode to high reduces the pumping effort required to more easily reach maximum pressure. It has a Twistgrip locking Presta/Schrader head to give a good, leak free seal. The Mammoth 2 Stage mini pump is nicely crafted from anodized aluminum for durability, good looks and performance.