Our GL10 single-shot sorption cooler adds an extra ultracold stage to the GL7. The load buffering provided by this additional stage enables the unit to reach a base temperature below 250mK, with sizeable heat buffering capacity at several temperatures points below 4K. It is even possible to add a second ultracold stage to the GL10 to increase the cooling power at the lowest temperature, see an example of the GL10 Twin in the Gallery.