A-Ok Starter Plugs™ are for starting seeds and rooting cuttings prior to plugging into larger Gro-Blocks™. The 1.5” size fits perfectly in the Gro-Smart tray as well as all our pre-drilled Gro-Blocks. One advantage of using the Gro-Smart tray is that it elevates the plugs above the waterline and ensures good airflow around the plugs. A-Ok plugs come labeled with instructions in a shrink-wrapped package that fits a standard 10 x 20 tray (flat). Detailed description: - A-OK PLUGS /MACROPLUGS : AO 36/40 (1.5” plugs) Size of Plug : 1.4" sq. x H 1.57" Plugs/Package : 98 - Plugs/Case : 2940 Package includes: 2940 x Grodan A-OK STARTER PLUGS 1.5'' 36 / 40 98 / SHEET