BettaMag is an even smaller magnetic window cleaner than NanoMag, for use in fish bowls, Betta bowls, pico aquariums and nano shrimp habitat displays. BettaMag cleans curved surfaces, is ideal for 1/8" thick glass/acrylic and suitable for use on aquariums up to 3/8" thick. Pad Size: 3/4" Long 1/2" Wide 3/16" Thick.