Elbow belt tensioner suitable for 2020 frame

Needs M3 x 30mm screw x 2 or longer one M5 x 30mm screw with M5 nuts or longer one At least 4 sets of M3 8mm screws and Ttype Sliding nuts At least 10mm OD x 3mm ID x 4mm ballbearing x 2 5mm ID 20 tooth GT2 idler pulley feature easy to ...