The Alpha Flash Jacket is simple, a neat fit, no hood and one small chest pocket. The Alpha Direct is the main fabric used, with a small strip of stretch material on each side of the torso and along the under arm.

Rab’s specification:

Weight: 273g/9.6oz
Polartec® Alpha™ Direct 120 insulation
Thermic™ brushed back single jersey with Polygiene® STAY FRESH odour control treatment
YKK® Vislon front zip, internal zip flap and chin guard
YKK® zipped chest pocket
Low bulk cuff construction
Half hem drawcord
Fit: Slim

I’ve used the Alpha Flash for a couple of months now, predominately out in winter. It’s has been useful for a light layer to have to hand when doing more local walks and some indoor ice & rock climbing.

The first thing that you notice is the Alpha Direct material, I’m used to the Alpha being sheathed in an outer and inner material. With it being “naked” the fibres and weave are revealed. The logic is this will allow the transfer of perspiration more rapidly and keep the heat in.

In practice the Alpha Flash wicks sweat like a demon, with it’s minimal cut it sits under a shell comfortably and with no restrictions from a solid outer the fabric moves with you, assisted by the stretch panels.

The downside to the open weave is its lack of wind resistance. I have worn it with a thick baselayer in a windy Coire with no shell and there was no chance it could battle with the chill and keep me warm. I also used it with vest / gilet in lesser winds and it worked nicely. Then the spindrift started to stick to it, so it was time to get a shell on.

My last Rab review said that they have good sized pockets, this is the exception. The only thing I could fit in it easily would be a point and shoot camera, in truth I didn’t use it. It could squeeze my phone it it (5.5 inch screen) but it’s not easy to take in and out. A smaller iPhone 6S fits in easily.

The look of the Alpha Flash is similar to a classic fleece although someone did comment it had the look of cardigan. I can see what they mean but it’s the most advanced “cardigan” on the market, in my opinion. With the Alpha Direct which has been impregnated with Polygiene there won’t be many cardigans that can do what the Alpha Flash does.

Where would I use the Alpha Flash? If I knew it wasn’t going to too windy and the weather was good then I’d use it over a base on a nice day, it’s wicking properties makes it a good option. Also, if it was going to be cold and damp and I was keeping my shell on then it would be good option too. Ski touring and other start-stop activities would suit this layer too. Rab do say it is the “alpinist's ultimate cold weather mid-layer.”

The Alpha Flash Jacket is certainly a useful mid-layer to be able to reach for. As I try to keep my shell off as much as possible, granted this is difficult in the Scottish climate, this limits the times I could take this with me on a day out, on a multi day it wouldn’t make to the final pack. It’s just not as versatile as other insulation layers with no water and very little wind resistance. Rab say this jacket “reinvents the traditional mid-layer”, I think the fabric has. I have more traditional mid-layer, or old fashioned fleeces, that I’d be happy to wear on a breezy summit on its own. Is this layer for you? Look at what you wear in the mountains: do you spend a lot of time with your hardshell on and baselayer underneath is not enough then the Alpha Flash Jacket would suit you. A light spring/summer layer, yeah this will work for you.