Medium weights weigh approximately 16.5 grams a piece and are 2-3/8" tall by 1-3/4" wide. The wearable surface measures approximately 13.4mm across and 7mm high -- you must be at least 1/2" to insert them.
Large weights weigh approximately 33 grams a piece and are 3" tall by 2-1/16" wide. The insertion gap is approximately 4.5mm. The wearable surface measures approximately 18mm across and 11mm high -- you must be at least 5/8" to insert them.