The Sim Shelf lets you place your PC or other control boxes neatly on a 5 mm thick black coated aluminium shelf. There are 2 types available, which are named afters the hole-to-hole distance. The 640 mm fits the P1 uprights, the 520 mm - 540 mm the GT1 Evo. 520mm is made for pre-2020 version of GT1 EVO while 540mm is designed for 2020 version.
Dept of the P1 version 250 mm, depth of the GT1 Evo version 220 mm.