Durable These bit holders and extension adapters are made of high quality carbon steel and chrome vanadium steel with heavy duty construction to ensure maximum durability. Ball detent design Ball detent design for quick connect or disconnect and ensure it stays in place while driving. Small size The small size allows you to bring your drill bit extension anywhere to do any job and can fit in many tool bags. Type There are one hex socket and three square adapters in different sizes and you can use the right one for various needs.SDS Plus - 65mm x 1/4" Square Head, SDS Plus - Square Head 65mm x 3/8", SDS Plus - 75mm x 1/2" Square Drive. MultifunctionalIt can be used for both drill bits and drill bits, making these extension adapters very practical and versatile. The universal SDS plus shank fits many electric drills and chucks. Features: Material: Stainless Steel & Chrome Vanadium Steel Type: SDS Plus - 65mm x 1/4" Square Head, SDS Plus - 65mm x 3/8" Square Head, SDS Plus - 75mm x 1/2" Square Head Quantity: 4 Package Includes: 3 x Square Extension Adapters Quantity delivery: 3 pieces / Set Product color: black Product size: diameter 10mm Note: manual measurement, please allow 1 - 3cm error!!!Yeuri 3 pices / Set Couleur du produit: noir Taille du produit: diamtre 10mm Note: mesure manuelle, veuillez permettre une erreur de 1 - 3cm!!!Yeuri