The SoftStop is a proprietary end terminal developed by Trinity Highway. The following summary was taken from their product website.
The SoftStop® System is a tangent, single-sided, energy absorbing, redirective and gating end terminal. The SoftStop® System is tested to MASH 2016 Test Level 3 criteria and may be used in Test Level 1, Test Level 2, and Test Level 3 applications.
During head-on impacts within MASH criteria, the SoftStop® System is designed to dissipate energy by the head traveling down the anchored W-Beam panels. During length-of-need side impacts within MASH criteria, the SoftStop® System is designed to contain and redirect the impacting vehicle.