Four Chinese characters - Chong Zhen Tong Bao (one-dot closed-head Tong) / Character Jiang above the hole. 23mm, 2.58 grams. Hartill 20.297 var (unlisted variety).  SKU T1081-50208

Listed for a two-dot Tong “ this variety with a one-dot Tong is not listed in the standard references. It might be a trial issue from a secondary mint or a trial of a different calligraphy. Very rare as such.