20.6mm x 1.55mm direct thermal path copper baseDedome Option. For additional fee, you can receive this LED dedomed and sealed. Dedoming increases throw, and shifts the temperature of the LED slightly warmer.
Why does it cost so much? The MT-G2 is one of the most difficult LEDs to dedome and the odds of damaging one during the dedoming process are high relative to most other LEDs. The LED is also very expensive. If the LED is significantly damaged during the dedoming process we bear that risk.
Why isnt' the LED face perfectly smooth? The MT-G2's die has a slightly raised and uneven phosphor layer, which means that it is impossible to get surface perfectly flat without also removing phosphor.