Energy Weapons - Extended Range Small Laser
The Small Laser is a free-electron laser which focuses a beam of light on targets to cause damage. The compact size of the Small Laser allows it to be equipped and used efficiently on practically anything; however the reduced firepower means that Small Lasers are not usually used on heavier combat devices such as 'Mechs or tanks. Small lasers can also be mounted on battle armor or used as an infantry support weapon by conventional infantry, where it is referred to as a "Support Laser."
Description provided by Sarna.Net
The Extended-Range Small Laser (ER Small Laser) focuses a powerful beam of light on targets that causes damage by overheating or melting the target.
As the name suggests, the Extended-Range variant of the Small Laser increases the power of the beam to project it to much farther ranges. The power necessary to facilitate the production of such generates an increased quantity of waste heat.
Unlike larger laser models, Small Lasers can be mounted on infantry, powered armor, or Elementals due to their small size.
As with most Clan energy weapons, the Clans lack their own standard Small Laser.
In MW:PR 3051 the ER Small Laser is just a less heat efficient version of the small laser with a greater range. It is best suited for self defense roles where the user would like an additional buffer space against enemy targets.