Horizontal adjustment range: 13-81mm, longitudinal adjustment range: 12-27mm Default size of drilling sleeve: 6mm/8mm/10mm/12mm Material of drill sleeve: stainless steel To meet the requirements of 6mm and 10mm two-in-one drilling 6mm connectors: use 6 and 10mm drill sleeves 8mm connectors: use 8 and 12mm drill sleeves Additional 15mm drill sleeve is optional (8mm 2-in-1 with 15mm cross hole nut) If you need 15mm drill sleeves, please contact customer service to replace them or purchase them separately.