Attached File
Attached File
Here's some comparison pics.
They are all on Vltor A5 7 position receiver extensions with IWC QD end plates and USGI castle nuts. The SL-K is 6 position, the SL and SL-S are 7 position, and the UBR 2.0 is 8 position. The SL-K is the shortest collapsed, followed by the SL, then SL-S, and finally the UBR 2.0. The SL-K is the shortest fully extended, followed by the UBR 2.0, then the SL, and finally the SL-S. The UBR 2.0 is 21.4oz/606g. The A5 receiver extension with hardware is 5.4oz/153g. The SL-K is the lightest combo and is the baseline. The SL is 1.7oz/48g heavier, the SL-S is 5.4oz/153g heavier, and the UBR 2.0 is 8.0oz/225g heavier.
The UBR 2.0 has to be at least one click out to use the front QD sling mount. Magpul's QDM is very hard to get in and out of the front sling mount and gets stuck when installed horizontally in the rear mounts.