Boost your Ballerina Brush Caddy with our brand-new Add-On! Each one adds 10 extra slots for your blending and detailing brushes. You can stack up to 9 add-ons on your Ballerina Brush Caddy Base. (Ballerina Brush Caddy sold separately.) The base already includes one add-on, giving you 20 brush slots total. Add-On height: 2″.