Currently, only one species, Trichoplax adhaerens, is acknowledged to belong to the Placozoa. The Italian Francesco Saverio Monticelli described another species in 1893, which he found in the waters around Naples, naming it Treptoplax reptans.
A standard mallet has a head length of 9 to 9.5, and this is recommended for beginners. Expert players may use longer head lengths up to 12, as this is thought to make aiming more accurate and makes it harder to accidentally twist the mallet during the stroke.
Printed enamel bracelets are available in size 65 (65mm diameter) and size 70 (70mm diameter) versions, as well as in size a 62 (62mm diameter) version for some models. The Clic H and Clic-Clac H bracelets are available in PM (Petit Model/small, 6cm diameter) and in GM (Grand Model/large, 6.5cm diameter).