Use a CoolBox 2XT Extension Collar when keeping tall tubes such as 3, 4, or 5 mL cryovials, 15 mL or 50 mL centrifuge tubes and blood collection tubes in the CoolBox 2XT ice-free cooling workstation.  

Place in between the the base of the CoolBox 2XT system and the original collar.  Magnets on top and bottom provide a secure connection to the base and original collar. 

Dimensions (L x W x H): Internal: 21.0 x 14.3 x 13.4 cm / 8.3 x 35.3 x 25.9 in
External: 26.5 x 20.0 x 15.0 cm / 10.4 x 7.9 x 5.9 in

CoolBox 2XT Extension collar is available in 4 colors
BCS-503-C, purple
BCS-503-CG, green
BCS-503-CO, orange
BCS-503-CPK, pink