The HECO-TOPIX-plus-T Solar in A2 stainless steel ensures a long-lasting and economical mounting of solar brackets on over-rafter-insulated roofs. The HECO-TOPIX-plus-T Solar features two patented wood threads with the same pitch. They guarantee a fixation at defined intervals, where the secondary thread fixes the counter batten and all the loads are transmitted via the thread directly into the rafters. The HECO-TOPIX-plus-T Solar screw is quick and easy to use without predrilling thanks to the patented "TOPIX" tip. The tip also prevents any risk of the counter batten splitting; meaning installation is quick and clean. With the screws flange haed, the roof hook or solar system fitting can be screwed flush and securely to the wood to form a connection that lasts.