ONA Block 175gr Hotbox Homegrown $15.00 Polar Crystal - $15.00 Fresh Linen - $15.00 Pro - $15.00 Quantity This variant is currently sold out Please fill in the form below if you'd like to be notified when it becomes available. Large performance. Small size. The Ona block is a small powerhouse when it comes to odor control. It can be put anywhere and forgotten until odors return.