<p>8Pcs Socket Adapter &amp; Extension Set. 1/4" hex drive size works for most quick change impact drills, power drills and hand tool ratchet. Spring-loaded ball bearing on head holds sockets securely. The 1/4" hex shank fits all quick change chucks as well as standard drill chucks.</p><br/><p>8 pcs &amp; 3 sizes: 1/4 x 25/30/50/65 mm, 3/8 x 50/65 mm, 1/2 x 50/72 mm</p>