Hizbollah was known to have received several thousand ATGMs over the years. Many of them are elderly, like the Russian Sagger. This is a 1960s design. It's a 24 pound missile, with a range of 3,000 meters, that must be carefully "driven" to its target via a joy stick controller. Requires a lot of practice to do right. The warhead is not very effective against tanks, but can do a lot of damage to buildings. Iran also sent some elderly TOW missiles, dating from the 1970s. These are too heavy to haul around. Lighter systems have proved more useful.
The French made MILAN ATGM, a 1970s design, has a 35 pound launch unit, firing a 16 pound, wire guided missile, with a maximum range of 2,000 meters. The Syrians got MILAN from France, and passed them on to Hizbollah. A similar Russian system, the 9M111 Fagot, has a 25 pound missile fired from a 24 pound launch unit. An even more modern Russian system, the Kornet E, is a laser guided missile with a range of 5,000 meters. The launcher has a thermal sight for use at night or in fog. The missile's warhead can penetrate 1200 mm of armor, which means that the front and side armor of the Israeli Merkava tank would be vulnerable. The missile weighs 18 pounds and the launcher 42 pounds. The system was introduced in 1994 and has been sold to Syria (who apparently passed them on to Hizbollah).
The Israelis quickly adapted to this Hizbollah tactic. The missiles are hidden all over southern Lebanon (buried, or tucked away in caves or buildings.) The Israelis have learned to get their snipers out, with their night vision equipment, to keep an eye on the most likely approach routes to the best firing positions. Hizbollah has been taking heavier losses than the Israelis, but neither Hizbollah, nor the Israelis want to talk about it. For Hizbollah, it's embarrassing to admit that, even with long range weapons, the Israelis nail their guys. For the Israelis, they don't want Hizbollah to know about new tricks, before those new ideas can be used at bit to find and kill the Hizbollah ATGM teams.
In Lebanon, Hizbollah found an interesting, if expensive, way to minimize the advantages Israeli infantry possess. The Israeli troops are much better trained, disciplined and led than the Hizbollah gunmen, so Hizbollah trained their fighters to try and stay away from Israeli infantry, and instead use ATGMs (Anti-Tank Guided Missiles) to fire at the Israelis from a long distance. This tactic has worked quite well, accounting for most of the Israeli casualties. Hizbollah has even hit a few tanks, but most of the ATGMs they are using are not powerful enough to do much damage to the Israeli Merkava tank. Other armored vehicles, and trucks, are much more vulnerable. Usually, however, the missiles are just fired at where the Israeli infantry are, in houses or trenches.