What is the U.S. Tomahawk Missile Used in the Syria Airstrike?

The Tomahawk Land Attack Missile (TLAM), the weapon used by the U.S. in a strike on a Syrian military airfield on Friday, has been a trusted part of the U.S. Navy's arsenal since Operation Desert Storm in 1990.
The cruise missile is 6.25 metres long (20 ft) and weighs in at 1,590kg (3,500 lb) according to its naval factfile.
Each missile has a payload of about 454kg (1,000lb), is extremely accurate and it can fly in a less than direct pattern to avoid being shot down en route to its target. The missiles are guided by GPS and according to manufacturer Raytheon they "can fly into heavily defended airspace more than 1,000 miles away to conduct precise strikes on high-value targets with minimal collateral damage. Launching the weapon from such a long distance helps to keep sailors out of harm's way."
Since 1995, with the acquisition of 65 Tomahawk missiles, the U.K. became the first non-U.S. military to incorporate the weapon into its arsenal. The individual cost per missile was US$569,000 in 1999, CNN reports, estimating that to be roughly US$832,000 today.