It's been a while, but I will give it a try.
The MK20 aka "Rockeye" is a standard cluster munition for light armor and some older tanks
From the DCS A-10C Manual:
CBU-105
The CBU-105 is the Wind Corrected Munitions Dispenser (WCMD) tail kit version of the CBU-97. Using Inertial Navigation System (INS) guidance, the CBU-105 can be dropped at much higher altitudes than the CBU-97 and guide to the targeted location (SPI).
Post edited because I was incorrect about the 99. I was confusing it with the 105. Apologies.