No LEDs and complicated stuff, a PCB, solder traces and connectors, that's what you get from ASUS if you are on a budget. 

The SLI connector is as such simple and has merely ASUS ROG branding printed on the PCB. The bridge comes with 60 mm or 2-slot spacing (1 slot between two dual-slot thick graphics cards).

The connector is HighBandwith, intended for Pascal and newer solution. For NVIDIA Pascal GPUs, the two interfaces are now linked together to improve bandwidth between GPUs. This new dual-link SLI mode allows both SLI interfaces to be used in tandem to feed one Hi-res display or multiple displays for NVIDIA Surround. Dual-link SLI mode is supported with a new SLI Bridge called SLI HB.
  

 
The bridge facilitates high-speed data transfer between GPUs, connecting both SLI interfaces, and is the best way to achieve full SLI clock speeds with say GeForce GTX 1080 GPUs running in SLI. Using this new SLI HB Bridge, GeForce GTX 1080’s new SLI interface runs at 650 MHz, compared to 400 MHz in previous GeForce GPUs using legacy SLI bridges. Where possible though, older SLI Bridges will also get a speed boost when used with Pascal. Specifically, custom bridges that include LED lighting will now operate at up to 650 MHz when used with GTX 1080, taking advantage of Pascal’s higher speed IO. 

The bridge will be sold separately, prices are unknown .. (but they can't be expensive).

ASUS Offers Simple NVIDIA SLI HB Bridge