2. Say hello to the new ACOS Pro adjustable coilover spacer with bump shocks. This kit features adjustable coil spacers packaged cleverly along with pneumatic/hydraulic bumpstops (aka air bumps). We love the idea of merging two great products into one. It makes the whole financial outlay thing easier to swallow. The kit comes with all the necessary hardware, illustrated instructions, and a set of 2-inch hydraulic bumpstops made exclusively for JKS by Radflo.