The iconic HK 416 rifles that are used by Polish Special Forces and other units such as the CAG, the DevGru or the USMC, apart from a number of advantages, also have several disadvantages, which include their weight and a small amount of aftermarket accessories.
The specifics of its design (it is a gas piston operated carbine and not a direct impingement operated like most AR15 designs), forces the use of mounting rails with a slightly different profile, which are not compatible with the AR15 system. There are only a few substitutes for HK handguards available on the market.
Here are the ones made by Geissele Automatics (SMR rails used by i.e. CAG),
Lancer
Strike Industries
and the very rare ones by Daniel Defense.
The KDG company probably wanted to fill this niche with their new handguard HK 556 M-Lok Rail System series.
As the name suggests, unlike the competition's models listed above, which use different rail section assembly systems, KDG handguards are made in the extremely popular M-Lok system, officially adopted by the USSOCOM.
The company offers handguards in two colors, black and brown (anodized) and in two lengths, 10 and 13.75 inches.
The systems are compatible with civilian carbines, i.e. the MR223 (European designation) and the MR556 (US designation) and versions for the army and uniformed services, i.e. the HK416 and the M27 (USMC). The price for the 10-inch version is 375 USD, for the 13.75-inch version you will have to pay 399 USD.
Prices seem competitive, especially in relation to Geissele products (about 500 USD) or DD (rails on the secondary market were recently sold for about 1200 USD).
Sources: soldiersystems.net, en.wikipedia.org, yahoo.com, operator-paramedyk.pl, tradingplacepawn.com, hkparts.net, lancer-systems.com, kineticdg.com
