Medium weights weigh approximately 19.8 grams a piece and are 2-3/8" tall by 1-5/8" wide. The wearable surface measures approximately 14.6mm across and 7.5mm high -- you must be at least 1/2" to insert them.
Large weights weigh approximately 28 grams a piece and are 3" tall by 2-1/16" wide. The insertion gap is approximately 3mm. The wearable surface measures approximately 18mm across and 11mm high -- you must be at least 5/8" to insert them.