The firm has the STC-7, STC-8 and STC-9. The main difference is the thermal conductivity, the STC-7 offers 7.2W/mK, STC-8 ups this to 8.3W/mK and STC-9 is the best of the pack with 9.1W/mK.
STC-7 and STC-9 ship in 4g syringes for 6.90EUR and 9.90EUR, repectively. STC-8 on the other hand is sold in a 1.5g container for 4.90EUR.
