The Strike King Pro-Model Square Bill Crankbaits are available in two series. The Series 1 is a small, shallow diver with a high buoyancy, which is designed to be thrown around heavy cover. The square lip design causes massive deflection to trigger strikes. The Series 4S features the same body design as the popular Series 4, but is designed for shallow applications. It crawls through all types of thick shallow cover with its unique wide wobble design and square bill. The shallow, cover-laden stained water domain of the spinnerbait angler can now be conquered with our Series 4S.