Sometimes you just want to hold a single frag to the glass. This is an official Ron frag plug, glued in to a socket on a super-strong rare-earth magnet .
Sold in pairs, each is 1.5" x .43" (38mm x 11mm).
Small: 1/8” (very strong) to 3/8” tank thickness.
Medium: Up to 5/8”.
Large: Up to 7/8” thick, please inquire (Made to order).
Note- At some point as the frag grows it will will either bond to the glass itself (encompass the entire magnet), or even grow big enough to exceed the capacity of the magnet's holding power. If it's become a "colony", its time to re-frag it and start over on the plug.