Bosch GFA 12-H Professional FlexiClick SDS AttachmentBosch GFA 12 H Professional FlexiClick SDS Attachment. Turns the FlexiClick drill driver into a SDS plus rotary hammer. Easy to operate. A 'One Click' interface ensures a tight fix to the machine at a glance. Suitable for hammer drilling up to 10mm into concrete and up to 16mm into masonry and stone. It is compatible with the 12V FlexiClick drill drivers GSR 12V 35 FC and GSR 12V 15 FC. For best working progress, use GSR 12V 35 FC.